The present report presents, partly, the collected VTI research on the "functional properties" of pedestrian and bicycle roads, and partly a survey of what has been done in this field outside of VTI. The term "functional property" has been interpreted in a broad sense, and basically everything connected with bicycle roads and bicycle traffic is included in the VTI literature review, which is the major part of the report. The operating environment analysis is made on the basis of the discussions from a seminar held at VTI, December 12, 2005, and complemented with literature reviews. The possibilities to build an instrumented vehicle for measuring bicycle roads, and the relevant properties of an evenness index, were discussed at the seminar. In the literature review, the research of VTI has been divided into five parts: traffic safety, maintenance and operation, mode choice, measurement of cycle flow, and the umbrella part "others". The research concerning traffic safety dominates, both at VTI and elsewhere. One of the conclusions from the project is that VTI should try to get funding to develop a measuring vehicle for cycleway surfaces. There is also a need to develop the unreliable methods used today (elastic tube and induction coil) to count bicycle traffic.

VTI and the Norwegian Institute of Transport Economics (TØI) have at the request of the Swedish Road Administration carried out a research and development project concerning tourist routes in Sweden. The project was done in two parts, one literature study with examples of how other countries work with tourist routes and one field study about the opinions of visitors and business operators along two Swedish tourist routes (the present publication). The two tourist routes which have been studied are Tourist Route Gränna-Ödeshög-Rök in the Counties of Jönköping and Östergötland, and Tourist Route Kullaberg in the County of Skåne. The study of the experiences of the business operators, the visitors' willingness to pay and a deepened analysis of the landscape was only done along the Gränna route. As for the experiences of the visitors the data for the two Swedish tourist routes have been compared with similar data from a Norwegian tourist route, Tourist Route Sognefjell.

Under hösten 2001, påbörjade Vägverket Region Stockholm arbetet med att ta fram ett regionalt cykelprogram. Programarbetet utgår från Vägverkets nationella strategi för ökad och säker cykeltrafik. Det regionala programmet ska visa Vägverket Region Stockholms mål, strategier och åtgärder inom cykeltrafikområdet under åren 2002-2006. VTI arbetar på uppdrag av Vägverket Region Stockholm med att kartlägga och sammanställa fakta om cykeltrafiken i regionen. Brister behöver identifieras för att Vägverket ska kunna välja lämpliga insatser och sätta upp rimliga mål för cykeltrafikområdet inom regionen. Den här enkätstudien ingår som en del i VTI:s arbete med att bygga upp nödvändig kunskapsbas. Enkäten syftade till att få en uppfattning om det cykeltrafikrelaterade arbetet i kommunerna i Stockholms län, som underlag för Vägverkets framtagande av ett regionalt cykelprogram. I enkäten har kommunerna även givits tillfälle att lämna synpunkter på vilken roll de vill att Vägverket ska ta i det fortsatta arbetet med att få en ökad och säker cykeltrafik i länet.

Syftet med denna studie är att undersöka om förekomsten av ett is-/snöväglag

utgör en högre olycksrisk i början och slutet av en vinter, i jämförelse med

själva "högvintern". Orsaken till detta skulle kunna vara, att förarna under

högvintern är mer förberedda på och vana att hantera ett is-/snöväglag än vad

de är i början och slutet av vintern. För att undersöka detta har

olyckskvoter beräknats, för tre olika långa för- och senvinterperioder. Dessa

olyckskvoter har sedan jämförts med olyckskvoten för motsvarande

högvinterperiod. Längden på högvinterperioderna varierade för olika delar av

landet. Olyckskvoterna uttrycks i antal olyckor dividerat med trafikarbetet,

där olycksmaterialet omfattar samtliga polisrapporterade olyckor på det

statliga vägnätet exklusive viltolyckor. Olyckskvotsberäkningarna har

differentierats på de fem väglag, som förekommer vid polisens

olycksrapportering: torr barmark, fuktig eller våt barmark, packad snö eller

tjock is, tunn is eller rimfrost, lös snö eller snömodd, där de tre

sistnämnda utgör is-/snöväglagen. Beräkningarna har även delats upp i sex

driftstandardklasser A1-A4 samt klass B1-B2 och med landet indelat i fyra

olika klimatzoner: Södra, Mellersta, Nedre norra och Övre norra Sverige. För

att beräkna trafikarbetet per väglag har väglagsfördelningar, baserat på

utförda observationer under vintersäsongerna 1993/94 t.o.m. 1996/97 samt

årsdygnstrafikarbetet använts som underlag. Analyserna visar att

olyckskvoterna för is-/snöväglag under före- och senvinterperioderna i nästan

samtliga fall är högre än för motsvarande högvinterperiod. Olyckskvoterna var

dessutom i de flesta fall högre under senvinterperioderna än under

förvinterperioderna. Det visade sig också att ju kortare för- och

senvinterperiod, desto högre var olyckskvoten i många fall. Dessa samband var

tydligast för vägar i driftstandardklass B1 och B2.

At the beginning and end of a winter season, there is a greater risk of car accidents in ice and snow conditions than during mid-winter. This was found in this Swedish study where accident data for four winters was correlated to road condition data obtained through visual observations. The purpose of the study was to see how the car accident risk on ice and snow varies over the winter. To examine this, the winter season was divided into three periods: Early winter, Mid-winter, and Late winter. Accident rates were calculated for each period and the values for Early and Late winter were compared with the corresponding Mid-winter values. The accident rate (car accident risk) is here defined as the number of accidents divided by the vehicle mileage, where the accident data includes all the car accidents on Swedish state roads recorded by the police, during the winter seasons from 1993/94 through 1996/97, excluding collisions with wildlife. Accident rates were calculated for five different types of road condition assessed by the police: Dry bare ground, Moist or Wet bare ground, Packed snow or Thick ice, Black ice or Hoar-frost, and Loose snow or Slush, where the last three are ice and snow conditions. The vehicle mileage for each road condition was calculated on the basis of visual observations performed to monitor the road condition. The analyses show that icy and snowy road conditions constitute a greater risk during Early and Late winter periods than during Mid-winter. The reason for this could be that drivers are more likely to expect these kinds of road condition during Mid-winter than at the beginning and end of the winter season. Moreover, the accident risk is greater during Late winter than during Early winter, and the shorter the Early and Late winter period, the higher the risk.

During the fall of 2021, the Swedish Transport Agency was commissioned by the Swedish Government to analyze and, if necessary, submit proposals for how changed traffic rules could lead to an increase in the proportion of road users who travel by bicycle. Against this background, the Swedish Transport Agency has engaged VTI, the Swedish Road and Transport Research Institute, to assist in the work by describing the state of knowledge based on current research in the relevant areas.

The aim of this study has been to investigate the spatial requirements of cyclists in different traffic situations and develop a basis for recommendations for designing cycling infrastructure regarding widths. Today, there are no rules or common construction practices for the physical design of cycle paths or cycle lanes in Sweden. Instead, it is up to each road authority to produce their own cross sections or recommendations and follow up on compliance.

The results in this report are based on literature studies regarding design standards and research on spatial requirements of cyclists. Recommendations are presented on minimum widths of cycle paths and cycle lanes depending on the possibility of meetings and overtaking, including consideration of cargo bikes, as well as safe distances to obstacles beside the road. An approach to model structure for assessing spatial requirements at higher flows of cyclists has also been developed.

The width of cycle paths can be varied depending on the desired dimensioning traffic situation. The dimensioning traffic situation is defined as the possibility of safe meetings or overtaking of a certain number of cyclists and pedestrians simultaneously on a cycle path or mixed-use path. From a maintenance perspective, however, it is advantageous to build bicycle infrastructure with a width of at least 2.5 meters, regardless of the traffic situation. Less width than that can result in lower efficiency for operation and maintenance with increased life cycle costs as a result.

Under hösten 2021 fick Transportstyrelsen i uppdrag av regeringen att analysera och vid behov lämna förslag till ändrade trafikregler för att andelen trafikanter som reser med cykel ska öka. Mot bakgrund av detta anlitade Transportstyrelsen VTI, Statens väg- och transportforskningsinstitut för att bistå i arbetet genom att beskriva kunskapsläget utifrån gällande forskning. 

Historiskt har dimensionering för gång och cykel baserats på ingenjörsmässiga uppskattningar med lite eller inget empiriskt underlag. Syftet med uppdraget har främst varit att undersöka cyklisters utrymmesbehov i olika trafiksituationer och att ta fram underlag till rekommendationer för utformning av cykelinfrastrukturens bredder. Idag saknas regler eller gemensam byggpraxis för den fysiska utformningen av cykelfält och cykelbanor. Det är istället upp till respektive väghållare att ta fram sina egna typsektioner eller rekommendationer och kontrollera efterlevnaden. Inom ramen för detta arbete har det bland annat tagits fram grundläggande designriktlinjer som beaktar cyklister och lastcyklisters utrymmesbehov och interaktion med andra trafikanter.  

Resultaten i denna rapport baseras på litteraturstudier gällande utformningsstandarder och forskning kring cyklisters utrymmesbehov. 

Arbetets primära resultat består i framtagandet av minstabredder för cykelbanor och cykelfält beroende på möjlighet till möten och omkörningar, inkluderat dimensionering för lastcyklar, samt trygga avstånd till sidohinder. En enkelrikta cykelbana för vanliga cyklister bör inte understiga 0,95 m bredd, plus 0,35 meter fritt avstånd till sidohinder utanför cykelbanan på varje sida. En dubbelriktad cykelbana bör inte vara smalare än 2,15 m, plus 0,35 meter avstånd till sidohinder per sida. Vid fullt beaktande av lastcyklar blir cykelbanebredden 3,5 meter på dubbelriktade cykelbanor. En ansats till modellstruktur för bedömning av utrymmesbehov vid högre flöden har även tagits fram. 

Utöver de faktiska breddrekommendationerna så har även arbetet resulterat i framtagandet av en lista med utformningsparametrar för cyklisters utrymmesbehov. Dessa parametrar beskrivs med måttangivelse och nivå av empirisk uppbackning. Vissa av parametrarna saknar fortfarande empirisk uppbackning vilket synliggör behovet av fortsatta studier.  

Objective: In Sweden, cyclists, pedestrians, and moped riders share the space on combined pedestrian and cycle paths, and their speeds may differ greatly. As a starting point, this article studies the speed component and how cyclists' speed varies at pedestrian and cycle paths depending on the day, week, and year; road user composition; and road design.

Methods: Three data sources were used: 1) Existing measurements of cycle speed and flow at 17 sites in 3 different Swedish municipalities; 2) complementary measurements of cycle speed and flow at 5 sites; and 3) roadside observations of bicycle types at these 5 new sites.

Results: The average speed of cyclists on the paths varied between 12.5 and 26.5 km/h. As expected, the lower average speeds were found in uphill directions, near intersections, and on paths with high pedestrian flows. The higher speeds were found in downhill directions and on commuter routes. In all, 70%-95% of road users observed on pedestrian and cycle paths were cyclists, and 5%-30% were pedestrians. The 2 sites with the highest proportion of electric-assisted bicycles and racer bicycles also had the highest average speeds.

Conclusions: The relationship between bicycle type and measured speed was not entirely clear, but the results suggest that paths with higher proportions of electric and racer bicycles have higher average speeds. There also appears to be a connection between average speed and the width of the distribution; that is, the higher the average speed, the wider the speed distribution. More research is needed on how speed levels and speed variance affect accident risk.

There is an objective of increasing cycling nationally, regionally and in many Swedish municipalities. The extent of cycling can be followed up with either travel surveys (TSs) or by measuring the bicycle flow. The Traffic Analysis Authority was commissioned by the Government to develop and propose a uniform method for systematic measurements of bicycle traffic at a local and regional level and their report was published in January 2018. Bicycle traffic can be measured in different ways and the two most common methods are (1) measurements by counting bicycles (manually or with detecting equipment) in the street area or (2) travel surveys (TSs). In this report, we focus only on counting cyclists in the street area. Today, the methods of counting bicyclists are limited, and they do not enable estimations of kilometers travelled by bicycle per average day in a municipality.

In order to achieve a broad application, it is necessary to investigate the possible obstacles that exist to use the Traffic Analysis's proposal for a uniform method, and this will be done in the following steps, where step 1 is described in this report:

1. A preparatory study: Suggest a set-up of a pilot study

2. Conduct a pilot study to establish a uniform and systematic approach, and finally

3. Determine the final uniform and systematic method.

The purpose of the preparatory study presented in this report is to adapt the Traffic Analysis's proposal to a uniform method for estimating the kilometers travelled by bicycle per average day, based on municipal conditions. The preparatory study will also lead to a proposal for a pilot study in which the adapted method is tested, and issues related to delimitations and definitions can be decided. The pilot study will be carried out in a follow-up project with a number of municipalities. This will result in a final determination of a uniform method for estimating the kilometers travelled by bicycle per average day.

During the last decades, cycling has been highlighted as a travel mode with many positive qualities. The documents of Swedish national strategy reveal a trend of an increased cycling. At the same time, it is important that the safety of cyclists must be improved so that an increased cycling does not contribute to more injuries and fatalities in accidents. To cope with the increased cycling without compromising the safety, there is fore example, a need for better understanding of the relationship between the cycling flow and the injuries in various traffic environments.

In this project, three different studies were carried out to understand how the trend of cycling changes over time and how cyclists' injury risk is influenced by the cycling flow and the traffic environment. In the first study, a travel demand model has been developed that includes both mode choice and destination choice for cycling. In the second study, models for cyclists’ injury risks have been developed for different types of accidents and traffic environments. In the third study, interactions between different road users have been observed, to study how these are affected by the level of bicycle flow. Overall, the studies in this project have shown that bicycle flow is an important factor influencing cyclists’ accident risks. Higher bicycle flow corresponds to fewer interactions per cyclist and a lower risk of injury in a single bicycle accident as well as in a collision accident with motorised vehicles. We have also been able to demonstrate that it is possible to model travel choices and destination choice of cyclists and to develop models that describe cyclists’ injury risk. However, to provide better estimates, data with better quality are necessary for the model inputs, especially when it comes to the cycling and the description of cycling infrastructure.

While cycling is promoted as a clean, energy-efficient mode of transport generating physical activity, the number of injured cyclists must decrease to achieve traffic safety goals. The extent of the single bicycle crashes (SBCs) and crash causes are rather well studied. This study expands this knowledge by focusing on differences in injury severity. The aim of the study is to investigate the relationship between injury severity and characteristics of the crash and the cyclist with focus on SBCs. Furthermore, injury risk is calculated for different age classes and sexes, as well as for different purposes of the trip. The results are based on injured cyclists in Sweden (N = 105,836) registered in STRADA, 2010–2019, by both the police and accident and emergency departments (A&Es), with a special focus on injury severity reported by the A&Es. Binary logistic regression was applied to analyse how the odds of being severely injured differed for different cyclists and situations. Results from of the National Travel Survey, 2011–2016, were used to study differences in distance travelled with respect to sex, age group and purpose of the trip. Given that the cyclist is injured in an SBC, the results show a higher probability of being severely injured (maximal AIS 3 or more) for cyclists 45 years or older compared to younger cyclists, for males compared to females and for cyclists not wearing a helmet compared to cyclists wearing a helmet. A higher probability for severe injury was also found for crashes occurring during leisure trips compared to work/school trips, crashes occurring during weekdays compared to weekends and crashes at intersections and road stretches compared to pedestrian and cycle paths. Furthermore, the risk of being severely injured in an SBC per km travelled was higher for cyclists aged 45 and older and during a leisure trip. © 2021 The Author(s)

The purpose of this paper is to enhance the understanding of cyclists’ speed on pedestrian and cycle paths and to understand how cyclists adapt their speed to other road users and the surrounding environment. The paper is based on a study where three different data sources were used: existing measurements of cycle speed and flow in three different Swedish municipalities, Eskilstuna, Linköping and Stockholm (19 sites); new measurements of cycle speed and flow in Linköping (4 sites) and Stockholm (1 site); and road side observations of bicycle types at these five sites.

The average speed of cyclists on the paths varied between 15 and 25 kilometres per hour. As expected, the lower average speeds were found in uphill directions, near intersections and on paths with high pedestrian flows. The higher speeds were found in downhill directions and on commuter routes. In all, 70–95 percent of the road users observed on pedestrian and cycle paths were cyclists while 5–30 percent were pedestrians. The most common type of bicycle used was a comfort bike, followed by a trekking bike. Electric assisted bicycles and racer bikes occurred at all sites, with a proportion of 1–10 percent and 1–15 percent, respectively. The relationship be-tween bicycle type and measured speed was not entirely clear, but the paths with higher pro-portions of electric and racer bikes generally had higher speeds. There also appears to be a con-nection between average speed and the width of the distribution – the higher the average speed, the wider the speed distribution. More research is needed on how this affects the accident risk.

Today, there is no defined national target level regarding increase in bicycling in Sweden. VTI received a governmental assignment to define that. The assignment includes a definition of a target structure and suggestion of indicators as well as a system for monitoring. We have gathered information through literature studies, a workshop, a survey as well as through own analyses of data from national travel surveys. We have limited the definition of cycling to include pedal cycle with or without electric assistance. Simply speaking, the rate of bicycling should double by 2035 and, more specifically, we suggest the following targets: 

• Overall objectives: Cycling in Sweden should increase to improve accessibility, strengthen public health, and decrease the climate and environmental impact. 

• Intermediate target 1: The bicycle share of the total number of travellers in Sweden should increase to 20 percent by 2030 and to 26 percent by 2035, without reducing the share of pedestrians or public passenger transports. 

• Intermediate target 2: The bicycle share of the total transport system work in Sweden should increase to 3 percent by 2035, without reducing pedestrians or public passenger transports. 

• Milestone 1: The total share of bicycle travel in Sweden, shorter than 10 km, should increase to 30 percent by 2030 and to 45 percent by 2035, without reducing the share of pedestrians or public passenger transports. 

• Milestone 2: The total share of bicycle travel for primary school children in Sweden should increase to 40 percent by 2030 and to 50 percent by 2035, without reducing the share of pedestrians.

 In addition, we have suggested seven indicators with associated measures linked to the targets suggested above. The national travel survey could be used to monitor the targets and the annual report by the National Council of Bicycling could preferably be used for monitoring the indicators.

Many different road users share space on pedestrian and cycle paths, and their speeds may differ greatly. Differences in speed can complicate the interactions between road users which in turn may cause incidents and accidents. The purpose of this project is to enhance the understanding of cycle speeds on the pedestrian and cycle paths and to understand how the cyclists adapt their speed to other road users and to the surrounding environment. Three different data collection methods were used: Previous measurements of cycle speed and flow in three different municipalities, Eskilstuna, Linköping and Stockholm (18 locations); new measurements in Linköping (4 locations) and Stockholm (1 location); and new observation studies of bicycle types at these locations.

The average speed of cyclists on the paths selected varies between 15–25 kilometer per hour. As expected, the lower average speeds were found in the uphill directions, near intersections and in paths with high pedestrian flow. The higher speeds were found in downhill directions and on commuter routes. No general increase in cyclists’ speed was found between years, neither in mean speed nor in proportion of high-speed cyclists. However, bicycle flow has increased in many of the locations over the years. This implies that the number of cyclists holding a high speed, above 30 kilometer per hour, will be increased, even if the proportion of high-speed cyclists stays the same. This may mistakenly be interpreted as increased mean speed. About 70–95 percent of the road users observed on the pedestrian and cycling paths were cyclists and roughly 5–30 percent were pedestrians. An extremely small proportion were mopeds, 0.2 percent. The comfort bike was the most common type, followed by the trekking bike. The electric and racer bike occurred in all locations, but varied 1–10 percent respectively 1–15 percent. The relationship between the type of bike and the speed claim is not entirely clear, but cyclists on the electrical and racer bikes generally have higher speed claims.

Det övergripande syftet med projektet "Trafiksäkerhet & Tillgänglighet vs Drift & Underhåll" är att finna lösningar på de konflikter som finns mellan de utformningslösningar som vi idag betraktar som tillgängliga och trafiksäkra och de problem som dessa utformningar utgör för drift- och underhållsarbetet. Ur ett helhetsperspektiv kan man idag få bilden av att man kanske fokuserar för mycket på att det ska vara optimalt ur ett trafiksäkerhets- och tillgänglighetsperspektiv, vilket i vissa fall innebär att det blir omöjligt att klara driften. Det i sin tur innebär att utformningen varken blir säker eller tillgänglig under vissa förhållanden. Vårt mål är att hitta lösningar som kan anses som tillräckligt bra ur ett trafiksäkerhets- och tillgänglighetsperspektiv och som dessutom går att sköta och ge godtagbar standard året om.

Operation of streets and roads, in addition to accessibility and safety, also affects environmental aspects such as air quality. Measures such as sanding and salting affect the content of inhalable particles (PM10) in the air. On the other hand, operational measures that are made to reduce the suspension of particles in the spring can have an effect on the winter operation, because the salt solutions used also act as de- and anti-icing agents. The project has investigated the possibilities of optimizing street operations from these aspects, with a focus on air quality. In various activities, views and experiences were gathered about problem images and solutions from industry, road managers and practitioners. A road dust sampler, WDS II, was developed. Evaluations of the effect of different coil and cleaning variants on the road dust load showed that a positive effect of the methods requires that there is relatively much dust on the road surface. Optimization tests showed that good forecasting of dust binding is important for a good result. A criteria-based analysis showed that no optimization of the dust binding occurred during the project period. Overall, the project's original goal of being able to propose an optimized street operation in a district in Stockholm has not been achieved, mainly due to current operating contracts and of the high priority of the environmental quality objective (PM10) and accessibility in the city. On the other hand, Optidrift has identified success factors and problems with the street operation, resulting in increased knowledge about the street operations' effects on dust load and air quality, and developed useful evaluation methods and scenario analyzes useful in continued work on improving and optimizing winter and barge operations.

This report is a literature review of the state of knowledge to understand the reasons for slipperiness on bicycle paths. The effect of texture on friction and slip risk and environmental impact is described. One of the main aims of the report is to present knowledge and needs around the friction and slip resistance of different types of surface courses under different conditions in cycle speeds up to 40 km/h. The slip risk is determined among others by the friction between the tire and the road surface. There are many factors that affect this friction, for example, the road surface's property, vehicle speed, tyre characteristics and the environment. This report focuses on the road surface's properties and meteorology (mainly temperature and humidity) and not on the bicycle or its component properties. The texture of the road surface is an important parameter when it comes to slip. The texture is divided into three wavelength ranges: micro, macro, and mega textures. Primarily, it is micro-texture and macro-texture that affect the friction of bicycles. In practice, the tire and the cycle path are rarely two clean surfaces that meets. Often, slip also occurs when the surface is dirty, water, snow and ice act as a friction-reducing layer between the wheels and the surface. Loose gravel also gives rise to slipping risk.

There are friction requirements for walking and cycling paths, although friction measurements are rarely carried out. Existing requirements in Sweden for surface course, including walking and cycling routes, are that the average friction number must not be less than 0.50 over a 20 meter long distance. Friction measurement can be done with PFT (Portable Friction Tester) as this hand-held instrument correlates well with the standard method Road (SAAB) Friction Tester which cannot be carried out on a bicycle path.

The purpose of this project was to define a useful methodology for comparing the ice grip of different bicycle tyres and to perform initial measurements. The long term objective is to set up recommendations to winter cyclists regarding bicycle tyres based on measurements performed according to the defined methodology. Measurements were done on smooth slippery ice using two regular (non-studded) bicycle tyres and four studded tyres of different brands and models. The tests were carried out in the VTI tyre test facility (TTF). The TTF is a unique indoor flat track machine for tyre tests on ice or asphalt pavement. This construction enables measurement of frictional forces under controlled conditions both when braking and steering. The TTF has been used for several years when testing tyres for both passenger cars and heavy vehicles, but to be able to test bicycle tyres some modifications of the equipment were necessary. The defined test method proved to be suitable for comparing studies. The measurements showed that studded tyres improve the grip on ice compared to regular bicycle tyres, but there can be differences in performance between different types of studded tyres. A larger number of studs is not necessarily related to a better grip on ice. When braking with locked wheel the frictional forces measured, were up to 2.5 times higher with a studded tyre compared to a non-studded tyre. In addition, studded tyres generally generate greater frictional forces when steering on ice compared to non-studded tyres. In general, a lower tyre pressure slightly increases braking and steering forces, but an optimal tyre pressure might be necessary in order to achieve the best possible performance from a studded bicycle tyre. Based on the results so far, cyclists should be recommended to use studded tyres when cycling during winter conditions. With an improved grip on ice and a better braking stability, there are safety benefits to be made.

In this project measurements of a bicycle tyre on an asphalt surface have been carried out in the VTI stationary tyre testing facility, in order to provide slip curves describing friction properties of the tyre. The measurement results have then been used to obtain tyre parameters for simulation purposes. The following tyre parameters have been measured: cornering stiffness, camber stiffness, brake slip stiffness and lateral relaxation length.

The tested tyre generated a maximum friction level of approximately 1.0 on the asphalt. Typical values of the tyre parameters were: normalized cornering stiffness 0.3; standardized camber stiffness 0.01; standard brake slip stiffness 250. Compared to the few previously published measurements on bicycle tyres, cornering stiffness was generally about 50 percent higher than previously reported. The values for camber stiffness correspond well to the values shown by a racing tyre study but are 25–50 percent lower than the values measured on more normal tyres in another study. For brake slip stiffness there are no previous measurements to compare with. Measurement of the lateral relaxation length was unfortunately affected by problems with the measuring equipment and we could not determine the relaxation length with the desired accuracy. From the measurements, we estimate the relaxation length to 200–300 mm for the tested tire, which is a factor 2–3 to greater than reported in the only earlier study that measured relaxation length for bicycle tyres.

The study aims to outline in which areas cycling has the potential to contribute to Sweden’s fulfillment of goals within the 2030 Agenda. 

The study is limited to main goals, sub-goals and indicators from the 2030 Agenda where cycling is deemed to contribute, positively or negatively. In the report, we have made a general overview of Transforming our world: the 2030 Agenda for Sustainable Development. In addition to a structured literature review of previous compilations of contribution of cycling to sustainability goals, the so-called snowball method has been used to search for literature in the field of cycling and the 2030 Agenda linked to specific goals. In the literature review, we have found two previous compilations of the connection of cycling to the 2030 Agenda and an action plan for physical activity with connection to cycling and the sustainability goals. ,

In this study, we do not have the ambition to try to quantify the contribution of cycling to the various goals, only that cycling has the potential to do so. Our system analysis shows that increased cycling contributes positively to several of the goals and that increased cycling at the expense of car traffic increases the positive contribution. At the same time, increased cycling can lead to more injured cyclists, which contributes negatively to the goals of the 2030 Agenda. However, safer cycling does not only reduce the negative contribution to the 2030 Agenda through injured cyclists, but is also a way to get more people to dare and want to cycle. It is important to consider various challenges in society as integrated, indivisible and deeply interconnected and to try to understand how the transport system contributes both in a positive and negative way if the ambition is to work based on the principles in the 2030 Agenda.

In this report, we present the results from a study commissioned by the research foundation of Länsförsäkringar (Länsförsäkringsbolagens forskningsfond). The aim was to develop and evaluate methods for testing how well-suited different bicycle lights are as vision aid, while at the same time making the cyclist visible and recognisable. Rather than comparing specific brands, the goal has been to evaluate generic features like brightness, beam shape, blinking versus steady beams, mounting position and so on.

Nine front and nine rear lamps from a wide price and design range have been selected from the bicycle lights available on the market. Brightness and beam shape were documented with lux measurements and via photographs. Six participants were asked whether they could, from a distance of 300 metres, identify front and rear lights and whether they showed a blinking, steady or rolling beam, and to rate the light setup for subjective preference. Gap acceptance and estimated ease of speed and distance judgements depending on beam type, mounting position and cyclist speed was investigated in a dynamic setting in an urban environment. Additional lighting features were demonstrated with films and photographs.

Current guidelines for work zones do not consider the needs of cyclists and pedestrians enough, which leads to unpredictable situations and a resulting higher crash risk for these road user groups. With respect to motor vehicles, speed management with various interventions is an important and well-studied measure. Their design can be hazardous for cyclists, but a systematic investigation of speed reducing interventions that are applicable to cyclists is lacking. In a controlled setting, four different types of interventions were studied regarding their effect on cyclist speed, attention, and comfort at the first encounter with the intervention and when familiar with the setup. Thirty cyclists with a variety of bicycles first rode a baseline condition to establish their desired speed, then they encountered the interventions eight times in a row. During the first encounter their speed dropped but went back to baseline levels during the following trials, regardless of intervention type. The glance behaviour showed that cyclists’ attention was focused much more on the interventions themselves than beyond, which can be problematic in unpredictable environments like work zones. Comfort ratings varied widely, with interventions causing vibrations being rated as least comfortable. To conclude, speed-reducing interventions for cyclists must be applied with care and their effect weighted against potential risks of causing crashes and distraction.

This report relates to a part of the government commission that the Swedish Transport Agency received in autumn 2021: to analyse and, if necessary, submit proposals on how an adaptation of traffic rules can promote safe overtaking of cyclists. The Swedish Transport Agency was also tasked to analyse the need for other changes to traffic rules that could lead to an increase in the proportion of road users travelling by bicycle. They engaged us to assist with a compilation of the state-of-the-art about cyclists' spatial requirements based on current research. That assignment only covered cycling on separated cycle paths and has been reported in VTI Report 1155 "Spatial requirements of cyclists - Knowledge basis for recommendations for designing cycling infrastructure". This report presents additional material that was compiled at the same time, but which was not included in the assignment from the Swedish Transport Agency.

This report compiles knowledge about spatial requirements of cyclists when being overtaken, mainly on rural roads, considering accessibility, traffic safety and security for cyclists. The report also touches on related issues such as the lateral positioning of cyclists and cycling abreast. These two topics also affect the spatial requirements on cycle paths, which means that parts of the information taken up here is also included in VTI Report 1155. The results in the report are based on an international compilation of regulations regarding cycling and relevant research literature with respect to "keeping to the right", "cycling abreast", "cycling on the road" and "overtaking of cyclists".

The research shows that measures are required to ensure that overtaking of cyclists by motorists in mixed traffic becomes safe and is perceived as safe by the cyclists. This is a basic prerequisite for increased and safe cycling, not least on rural roads. Possible measures are rule adaptations (which is discussed in the report), information campaigns or improvements to the infrastructure for cyclists. A difficulty with today's regulation is determining what a "safe distance" implies. Further research on the topic is needed to be able to provide clearer guidance.

This report relates to a part of the government commission that the Swedish Transport Agency received in autumn 2021: to analyse and, if necessary, submit proposals on how an adaptation of traffic rules can promote safe overtaking of cyclists. The Swedish Transport Agency was also tasked to analyse the need for other changes to traffic rules that could lead to an increase in the proportion of road users travelling by bicycle. They engaged us to assist with a compilation of the state-of-the-art about cyclists' spatial requirements based on current research. That assignment only covered cycling on separated cycle paths and has been reported in VTI rapport 1155 "Spatial requirements of cyclists - Knowledge basis for recommendations for designing cycling infrastructure". This report presents additional material that was compiled at the same time, but which was not included in the assignment from the Swedish Transport Agency.

This report compiles knowledge about spatial requirements of cyclists when being overtaken, mainly on rural roads, considering accessibility, traffic safety and security for cyclists. The report also touches on related issues such as the lateral positioning of cyclists and cycling abreast. These two topics also affect the spatial requirements on cycle paths, which means that parts of the information taken up here is also included in VTI rapport 1155. The results in the report are based on an international compilation of regulations regarding cycling and relevant research literature with respect to "keeping to the right", "cycling abreast", "cycling on the road" and "overtaking of cyclists".

The research shows that measures are required to ensure that overtaking of cyclists by motorists in mixed traffic becomes safe and is perceived as safe by the cyclists. This is a basic prerequisite for increased and safe cycling, not least on rural roads. Possible measures are rule adaptations (which is discussed in the report), information campaigns or improvements to the infrastructure for cyclists. A difficulty with today's regulation is determining what a "safe distance" implies. Further research on the topic is needed to be able to provide clearer guidance.

In darkness it is legally obligatory to light vehicles, both to enable their operators to see where they are travelling and to make the vehicle visible and recognisable to other road users. Legal requirements differ between vehicle types and, for bicycle lighting, also between countries. So far, in spite of some indications, there is no definite evidence of a relationship between crashes involving cyclists and darkness, nor on the presence of bicycle lighting and crash risk in darkness, possibly due to a lack of prevalence data. There are no standards for scientific or consumer testing of bicycle lights, and visibility-related results are inconclusive. Three test methods were employed to evaluate generic bicycle light features such as beam shape, brightness, steady versus flashing beam, and mounting position for their effects on seeing and being seen, while investigating which method was best suited for which type of evaluation. In static indoor laboratory testing, brightness was measured and beam shape documented photographically. In static outdoor testing, visibility from 300 m was evaluated, subjective ratings were collected, and beam shape documented. Three front-light beam types were then evaluated for their effect on gap acceptance in a dynamic setting in an urban environment, and subjective ratings were collected. All 18 tested lamps fulfilled the legal requirements, with a bright, steady front beam receiving the highest subjective ratings. Gap acceptance was influenced only by cyclist speed, but neither by beam type nor mounting position. To capture the effect of generic bicycle light features on perception, behaviour, and acceptance, one single method is not enough, and standardised laboratory tests should be combined with research-question–specific dynamic testing. © 2021 The Authors

There is a need to move society in a sustainable direction. One way to contribute to this move is to change to more sustainable transport modes, such as cycling. To increase cycling, the infrastructure is important, and good quality cycle paths are needed. However, little is known about the degradation of cycle paths. This paper aims to investigate what modes of pavement distress are found on municipal cycle paths in Sweden, and what probable mechanisms lie behind such distress; these are determined based on questions from a state-of-practice survey, interviews, and a literature review. The main findings are that the most commonly stated distress modes are surface unevenness followed by longitudinal cracks, and the most commonly stated causes of distress are ageing, followed by structural interventions, and roots and vegetation. The results also show that for several distress modes, there are probable connections with climatic factors such as temperature and moisture, as well as with the population size of the urban areas. Objective data are needed regarding traffic load and the climatic factors that affect cycle paths, along with information on their structural design, to better understand their degradation.

The riding comfort of cyclists related to roughness and unevenness of cycle path surfaces has unfortunately not been given enough attention in the indices used to predict cyclists’ perceptions of roadway environments. This is partly due to the lack of condition assessment methods specifically adapted to the speed and space limits on cycle paths, and a need for developing metrics that describe the perceived comfort of cyclists rather than that of car users. In this paper a novel method, the Bicycle Measurement Trailer (BMT), is proposed to bridge this gap. Eight different surface types, ranging from gravel and different sized concrete block pavements to asphalt concrete in different conditions, have been assessed with regards to roughness. Four of these surfaces were also used for the assessment of their longitudinal evenness. The accuracy and repeatability of the BMT were evaluated. Finally, five different metrics (Dynamic Comfort Index, Evenness Coefficient, 0.5 m Straight Edge, International Roughness Index and Root Mean Square), were calculated from the collected data and assessed. The main findings suggest that the BMT has a high accuracy at normal and high cycling speeds when compared to the standardized road measuring system, Road Surface Tester, and a high level of repeatability at normal cycling speed. The surfaces could be ranked according to their roughness, and the longitudinal evenness was successfully analysed from the collected data. In conclusion, the BMT could be a valuable tool to assess the cycle path surface condition in relation to how cyclists perceive the riding comfort.

Cyclists’ riding comfort, related to pavement texture and unevenness, has not been thourougly investigated, partly due to the lack of condition assessment methods specifically adapted to the speed and space limits on cycle paths. Metrics that better describe the perceived comfort of cyclists, rather than that of car users, are needed. In this paper a novel method, the Bicycle Measurement Trailer (BMT), is proposed to bridge this gap. Eight different cycle path surface types have been assessed with regards to pavement texture and for four of these surfaces the longitudinal evenness was assessed. The accuracy and repeatability of the BMT were evaluated. Finally, five different metrics (Dynamic Comfort Index, Evenness Coefficient, 0.5 m Straight Edge, International Roughness Index and Root Mean Square), were calculated from the collected data and assessed. The main findings suggest that the BMT has a high accuracy at normal and high cycling speeds and a high level of repeatability at normal cycling speed. The surfaces could be ranked according to texture, and the evenness was successfully analysed. In conclusion, the BMT could be a valuable tool to assess the cycle path surface condition in relation to bicycle riding comfort.

Introduction: Active school transportation (AST) can be a powerful strategy to promote physical activity and improve children's health. Parents' perceptions of traffic risks are an important factor in their decision concerning their child's transport mode to school and addressing discordances between the percieved risks and actual incidents might contribute to promote children's AST. This study adopted a game originally designed for the context of information security to resonate with the context of Swedish AST and the aim of the study was to describe parent's experience of playing the game. Methods: A qualitative approach was chosen and data was collected using focus groups with 16 parents for totally 29 children aged 7–12. The collected data were analyzed using qualitative content analysis. Results: The results formed one main theme “Playing promotes parents' awareness and consideration of active school transportation” and three subthemes; “Fast, fun, and functional; Experiences from playing the game” showing that the parents perceived the game to be fun, easy, and time efficient to play. “Then and now. Own childhood experience vs being a parent” showing that parents' perception of risk can sometimes be barriers to their children's opportunity to use AST. “Personal perceptions vs statistical risk” showing that playing the game addressed the discordance between the parents' perceived risks and actual incidents, as well as promoted parents' awareness and consideration of AST. Conclusions: Including an intervention component such as a game for parents and using schools as the arena for implementing projects promoting AST to improve children's physical activity levels, might be a fruitful avenue.

Research and new knowledge are important parts in achieving the government’s goal more and safer cycling contributing to a sustainable society and a high quality of life throughout the country. VTI was therefore assigned to compile and analyse the needs in cycling research and analyse how cycling research in Sweden can be coordinated and strengthened. The results are presented in this report giving examples of issues related to cycling that need to be scientifically strengthened through basic as well as applied research. This includes, for instance, the practical integration of cycling in traffic- and urban planning and knowledge on effective measures where special needs, prerequisites and barriers in groups of existing and potential cyclists are considered. Research describing cause and effect relationships regarding the design, construction, operation and maintenance of cycling infrastructure is required in order to carry out socioeconomic evaluations of cycling measures. Decisions also need to be based on research in order to prioritise between various types of measures and motivate measures to decision-makers. This also applies to information and campaigns.

To generate cause and effect relationships, cycling and cycling accidents need to be better followed up, and a more detailed description of the cycling road network is required. Moreover, traffic models for cycling need to be developed, and more research about the actual bicycle and its equipment is required. Overall, there is a great need for long-term knowledge building and competence provision, increased coordination of cycling research and a more efficient distribution and application of research findings. To fulfil these needs and create better prerequisites for more research on cycling, it is of great value that a national knowledge centre for cycling research and education has been established at VTI in Linköping, Sweden. At the cycling research centre, the following important tasks should be carried out: Long-term knowledge building, connecting research and problem owners, coordinating research and development, gathering and distributing knowledge, developing technical resources, measurements and measurement methods.

This study gives an insight into the routines and regulations for cycleway maintenance in Sweden, based on interviews with employees in 13 municipalities with relatively high amount of bicycle traffic. The study is part of a project, "service levels of cycleways", with the purpose of improving cycleway maintenance in order to promote cycling. In general, for cycleway construction, the municipalities follow the technical description of road constructions from the Swedish Road Administration. However, for maintenance of cycleways, the municipalities have their own requirements. Budget restraints are usually determining the requirements and limited means are considered to be the major obstacle to provide a high service level. Yet, cycleways are given priority and are maintained at the highest service level in most municipalities. Thawing and freezing, resulting in slush followed by icy ruts and slipperiness, is considered to be the most difficult condition to handle in cycleway maintenance, as well as providing good quality surfaces in view of cyclists' sensitivity to even minor defects. Cycleway surface conditions are monitored through visual inspections only. The public is considered to be an important resource in detecting cycleway defects, and their remarks are systematically registered. The most common complaints regard broken glass or slipperiness.

This is the final report within the research project "Service levels of cycleways" with the purpose of finding the characteristics of an attractive cycleway, and specifying how to maintain cycleways in order to promote cycling. The report is based on literature reviews and summarizes also the studies conducted in the project including interviews with employees in Swedish municipalities, focus group studies with cyclists, as well as test and evaluation of a method for measuring the surface evenness of cycle paths.

The maintenance service level of cycleways is important in order to raise the status of the bicycle as a mode of transport. In Sweden more than 70% of bicycle accidents are single vehicle accidents and 40% of those are maintenance related. Skid control is the most important maintenance measure for the safety of cyclists, while snow clearance is crucial for travel time and accessibility. Surface unevenness as well as grit, broken glass, etc. also affect the safety of cyclists, but are more crucial for their comfort and travel time.

Requirements and recommendations are based on experience and common knowledge rather than on the effects for cyclists, and it is usually the requirements for roadways as well as budget restraints, that set the limits. In consequence, there is a difference in the maintenance service level perceived by cyclist compared to the one declared by the road administrators.

This study describes the significance of various road related factors for cyclists' accident risk, accessibility, comfort and decision whether or not to cycle. Four focus group meetings with cyclists from Linköping and Umeå were held, following an interview guide with six principal areas: avoidance of obstacles, the cycle ride takes longer than necessary, or longer than usual/planned, increased stress, safety risk, and the decision whether or not to cycle. Apart from the principal areas in the interview guide, the participants' comments were grouped under the categories maintenance, geometric design, other road users, traffic rules and other matters. For the safety risk, other road users and geometric design appeared to have the greatest significance, as well as shortcomings in maintenance. Exercise and wellbeing were the chief reasons to cycle. Maintenance is also significant for the decision to cycle, mainly in the winter, but this chiefly applies on the part of those who regularly cycle in their daily decision. To promote cycle traffic it is essential to enhance the competitiveness of the cycle by improving accessibility and making travel times shorter for cyclists. This mainly requires a direct and continuous cycle path network. Maintenance of high standard has a more immediate effect on accessibility during short periods, and it is important in retaining the existing cyclists.

The aim of this study is to augment the Accident Risk Model (within the Winter Model) with accident risk and the consequences of different types of accident, in order that the costs of accidents in icy and snowy road conditions may be calculated. We have calculated the accident risk by dividing the nutuber of accidents by vehicle mileage for the winters of 1993/1994 through 1996/1997. In this study, we have grouped accidents into four types: single-vehicle accidents, head-on collisions, rear-end collisions and other accidents. For all accident types the accident risk is higher on icy and snowy roads than on dry bare roads. Head-on collisions and single-vehicle accidents have the highest relative accident rates, with accident risks that are more than ten times higher in snowy and icy road conditions. For single-vehicle accidents, it is the thin ice/hoar frost that is the main cause of this great increase. Generally, the consequences of head-on collisions are more serious on roads with snow and ice than on dry bare roads in the wintertime, while for single-vehicle accidents the consequences are less serious. We have calculated the consequences by dividing the nutuber killed, severely injured and slightly injured by the total number of accidents. For these calculations, accident data for all winters during the whole of the 1990s have been used.

Single bicycle accidents represent more than 70% of all bicycle accidents in Sweden and the biggest influencing factor is slippery surfaces, mainly caused by ice and snow. In addition, the winter maintenance service level is significant for the accessibility of cyclists and for their decision to cycle or not. According to road maintenance administrators the most difficult conditions to manage in cycleway maintenance is thawing and freezing, resulting in slush followed by icy ruts and slipperiness. In this paper, winter maintenance of cycleways will be discussed from various perspectives, based on several studies performed at VTI. The effects on safety related to winter maintenance is estimated using accident data based on reports from hospital emergency rooms. In total, almost 18 000 bicycle accidents were analysed. The paper will also present the opinion of cyclists concerning the importance of the winter road condition for their perceived safety, their travel time, etc. The results are based on focus group studies performed in two Swedish cities with different climate and daylight conditions. The cyclists’ opinion will also be compared to the perception of road maintenance administrators. Road maintenance administrators from 13 different municipalities in Sweden have been interviewed.

Considering the safety of cyclists and pedestrians the winter maintenance service level needs to be improved and there is a need for skid control measures that are effective and, at the same time, reduce the amount of grit spread during the wintertime. Warm wetted sand, a method were the sanding material is mixed with hot water while spreading and were the sand adheres to a cold surface through a process of melting and freezing, could be the solution. In this study, the applicability of using warm wetted sand on walkways and bike paths has been evaluated in Umeå municipality during the winters of 2010/11 and 2011/12. Comparing measurements of friction clearly showed higher levels of friction improvements and with a longer duration when using warm wetted sand for skid control on walkways and bike paths compared to traditional dry sand. The study also showed that the number of actions can be reduced when using warm wetted sand instead of traditional dry, and it is therefore possible to reduce the amount of grit spread. The method was most effective on sections with on-street-cycling were the road condition more often is thick ice. The apprehension that the method might create an uneven surface uncomfortable for cyclists was not perceived. The maintenance operators had, on the other hand, noticed that when spreading warm wetted sand on soft packed snow an uneven surface might occur, if the warm sand melts through the top layer of the snow surface. The main problem with the method is the freezing of the sand material in the hopper and the spreader, due to the high amount of fine graded particles in the sand mixture. The results are not promising enough to motivate an investment in equipment for skid control on walkways and bike paths only, but with a multi-purpose use it gets more cost effective.

Sopsaltning av cykelvägar är en metod som skulle kunna bidra till en högre standard på cykelvägarna vintertid. Med metoden kan man undvika problematiken med rullgrus. Några svenska kommuner arbetar i dag med att sopsalta cykelvägar. VTI har gjort utvärderande mätningar av sopsaltning i Stockholms stad som sedan vintern 2013/2014 tillämpar metoden ganska omfattande. De utvärderande mätningarna som VTI har gjort på uppdrag av Stockholms stad finns kortfattat beskrivna i detta häfte.

To encourage people to cycle during winter and at the same time reduce the number of single bicycle crashes, a high winter maintenance service level is needed. Traditionally in Sweden, ploughing and gritting is used for winter maintenance of cycleways and footways. In recent years, a method using a front-mounted power broom for snow clearance and salt for de-icing (commonly called “sweepsalting”) has become popular for winter maintenance of cycleways in Swedish municipalities. Linköping was the first municipality to test the method, already in 1999. Today, municipalities from Umeå in the north to Malmö in the south are applying the method with a variation in methods, equipment and strategies. In this project earlier research has been complemented with detailed field studies in Linköping and Stockholm, theoretical knowledge as well as practical experiences from several Swedish municipalities. The objective has been to provide a better understanding regarding pros and cons of “sweep-salting” as well as the equipment, methods and strategies appropriate under various conditions. The studies presented in this report show that when working successfully, the sweep-salting method creates a bare surface with higher friction than traditional ploughing and gritting. Measures must be done in time and the operating speed adjusted according to the prevailing conditions. In mild weather brine is sufficient, but with lower temperatures and heavy snowfall larger amounts of salt is needed and pre-wetted or dry salt must be used. For the method to work properly, the bicycle path construction should be of good condition without cracks or other damages in the surface. The equipment for sweep-salting needs to be further developed for a higher efficiency.

Under vintern 2012/13 testade Stockholms stad några olika utrustningar för sopsaltning på utvalda cykelvägar i Stockholm och sedan vintern 2013/14 pågår en mer omfattande tillämpning av metoden på några utvalda cykelstråk viktiga för arbetspendling. Väglagsobservationer visar tydligt att sopsaltningen resulterat i ett bättre väglag än traditionell plogning och sandning. Resultaten redovisas i detta notat. Målsättningen inför vintern 2013/14 var att hålla en mycket hög standard på de utvalda cykelstråken. Under hela vintersäsongen skulle förarna köra sina sträckor i princip varje vardag, oavsett om det behövdes någon vinterväghållningsåtgärd eller inte. I början av vintern skulle sopningen bidra till att göra cykelstråken fria från smuts, kvistar, nedfallna löv etc. Vid risk för halka skulle det också saltas, så länge temperaturen var över -12°C. Vintern blev som helhet mycket mild, det snöade endast vid ett fåtal tillfällen och i de flesta fall bara måttliga snömängder. Det innebar att det aldrig fanns något behov av att gå över till plogning och sandning utan metoden med sopsaltning var tillämpbar hela den aktuella vintern. Väglagsobservationer visar tydligt att sopsaltningen resulterat i ett bättre väglag än traditionell plogning och sandning. Det har i princip alltid varit barmarksförhållanden på de sopsaltade stråken, även då det varit snö och is på cykelstråk som inte saltats. VTI:s mätningar visar också att friktionen i genomsnitt varit betydligt högre på de sopsaltade stråken jämfört med de stråk som inte saltats. VTI:s friktionsmätningar visar emellertid att friktionen kan variera ganska mycket längs de sopsaltade cykelstråken. Medan ”orörda” delar av stråken har mycket god friktion, kan skador i beläggningen, indrag av snö från osaltade stråk, korsningar, vägmarkeringar och brunnslock uppvisa en låg friktion.

Inför vintern 2013/14 fick VTI i uppdrag av Stockholms stad att utvärdera tillämpningen av sopsaltmetoden för vinterväghållning av ett antal prioriterade cykelstråk i Söderort och Västerort. I detta notat sammanställs de mätningar som gjordes under vintern 2014/15. Sopsaltmetoden innebär att en sopvals används för att röja bort snön från vägytan och att halka bekämpas med saltlösning eller befuktat salt. Eftersom försöken 2013/14 ansågs lyckade så utökades det sopsaltade cykelvägnätet till det dubbla och totalt 12 mil cykelväg sopsaltades under vintern 2014/15. I januari 2015 var det relativt stora nederbördsmängder vilket satte metoden på prov. Uppföljningen har under båda vintrarna bestått av stickprovsvisa mätningar i ett antal utvalda punkter som representerar olika typmiljöer och olika sopsaltmetoder/-utrustningar. Där har friktionen, väglaget, saltfördelningen och saltmängderna studerats. Dessutom har åtgärderna följts upp med förarprotokoll och väderdata. I samband med de stora nederbördsmängderna i januari, blev det problem med isbildning på de sopsaltade cykelstråken i Stockholm. Vid kraftig fukttillförsel eller nederbörd sker en utspädning av saltet vilket kan leda till en uppbyggnad av isbark. Vid dessa tillfällen skulle man alltså ha behövt lägga en större saltmängd för att undvika isbildning. Vinterns utvärderingar antyder att problemen med isbildning tycks vara värst på gångbanor med höga fotgängarflöden. En lärdom är att om isbark väl uppstått, är det bättre att snarast gå över till att sanda istället för att försöka få bort isbarken med salt – naturligtvis beroende på rådande väderförhållanden och vad prognosen säger. Vid omslag till varmare temperaturer kan man riva/ploga bort isbarken och återigen övergå till sopsaltning.

Detta notat innehåller en analys över tänkbara för- och nackdelar med sopsaltning på cykelvägar i Karlstad. Stadens läge och klimat talar för att sopsaltning av cykelbanor skulle kunna vara en användbar metod vid vinterväghållning. Många städer gör nu satsningar för att andelen resor som sker med cykel ska öka även vintertid. En vinterväghållningsmetod som vuxit kraftigt är sopsaltmetoden där en sopvals röjer bort snön och halkan bekämpas med saltlösning eller befuktat salt. På så vis undviker man att sand ansamlas på cykelbanorna, men i gengäld sprider man mer salt. VTI fick i uppdrag av Karlstad kommun att analysera tänkbara för- och nackdelar med sopsaltning på cykelvägar i Karlstad och ge rekommendationer för en eventuell fortsatt tillämpning av metoden. Analyserna bygger på teoretiska samband och en kartläggning av genomförda åtgärder under vintern 2014/2015. Åtgärderna har kopplats till rådande väderförhållanden genom analyser av data från Trafikverkets vägväderinformationssystem, VViS. Forskarna har också beaktat allmänhetens synpunkter genom att ta del av genomförda enkäter, Facebook-inlägg och ärenden inkomna till kommunens kundcenter rörande vinterväghållning av gång- och cykelvägar.

Skidding is a common cause for cyclists getting seriously injured in traffic. Neither requirements nor prescribed friction measurement methods for cycleways have been based on the performance of bicycles. There is therefore a need for increased knowledge regarding the friction characteristics of bicycle tyres and the traction between a bicycle tyre and the road surface under different conditions. In this project we have compiled measurements with VTI's portable friction tester, PFT, on cycleways with a variety of road conditions. To relate the PFT friction values to the friction of bicycle tyres, we have also made comparative measurements with bicycle tyres in VTI's stationary tyre testing facility. These show a very good match between the PFT friction values and the maximum lateral friction available for a bicycle tyre. This means that the PFT friction values recorded on cycleways can also be said to represent the friction that a bicycle tyre would perform on the same surface. Our friction measurements on cycleways show that the skid resistance is affected by the road condition, the road surface material, as well as road markings and manhole-covers. Ice and snow cause a significantly lower friction level than at bare conditions. Differences in road conditions mean that different types of cycling infrastructure and different winter maintenance methods result in different friction levels. This means that there may be large variations in friction along one and the same cycle route. The surprise effect and thus the accident risk can then be great. Not only snow, ice and grit, but also leaves, clay and other dirt on the surface might lead to a reduced skid resistance. For the safety of cyclists, it is important to inform about where a slippery condition can occur and to adjust anti-icing actions, road design and construction according to that knowledge.

In Stockholm, cycling as a mode of transport is promoted, especially for commuting. Public transport as well as the roadway network has reached capacity during peak hours and cycling is considered to be an advantageous alternative, since there are environmental and health benefits to gain. To encourage people to cycle during winter and at the same time reduce the number of single bicycle crashes, a high winter maintenance service level is needed. Using salt for skid control of bicycle paths could be one solution, although it has its drawbacks and difficulties. In recent years, a method using a frontmounted power broom for snow clearance and salt for de-icing (commonly called “sweep-salting”) has become popular for winter maintenance of bicycle paths in Sweden.

In 2013 the city of Stockholm decided to try the “sweep-salting” method and evaluate its potential to improve the service level on bicycle routes for commuting. To optimize and develop the method, VTI has performed field studies every winter since 2013. These studies have included measurements of friction, road condition observations, measurements of residual salt on bicycle path surfaces, salt deposition at the side of bicycle paths, maintenance protocols and interviews with maintenance operators. Since all studies were done in field, in a real-life environment, the experimental work was designed according to the winter maintenance routines of the municipality and other prevailing conditions and circumstances. This report presents the results from the evaluation of the winter of 2016/2017.

The evaluations show that when working successfully, the sweep-salting method creates a bare surface with higher friction than traditional ploughing and gritting. Measures must be done in time and the operating speed adjusted according to the prevailing conditions. In mild weather brine is sufficient, but with lower temperatures and heavy snowfall larger amounts of salt is needed and pre-wetted or dry salt must be used. For the method to work properly, the bicycle path construction should be of good condition without cracks or other damages in the surface. Otherwise, it is difficult to clear the surface with the broom as snow and water can be trapped in potholes and cracks, eventually creating ice patches. A sufficient drainage from the surface is also crucial as every contribution of water will dilute the salt amount on the path with a following risk of creating a slippery surface. Narrow passages and obstructing design features cause difficulties when clearing the snow, resulting in a need of larger amounts of salt to prevent icy conditions. Clearing the surface from snow and water is crucial to get a good result with the method.

Den här handboken har tagits fram av Statens väg- och transportforskningsinstitut (VTI) i samarbete med Karlstad kommun. Underlaget till handboken har tagits fram med stöd från Vinnova baserat på forskning finansierat av Trafikverket och Stockholms stad. Handboken har färdigställts och kompletterats med mallar, filmer och andra beslutsstöd tack vare finansiering från FORMAS inom det nationella forskningsprogrammet för hållbart samhällsbyggande.

Syftet med den här handboken är att sammanställa driftinstruktioner och saltmall för sopsaltning på cykelvägar baserat på teoretisk kunskap insamlad i forskningsstudier kombinerat med praktiska erfarenheter hos driftledare och förare. Målsättning har varit att på ett kortfattat och enkelt sätt ge praktiska råd och tips om planering och förberedelser, genomförande och utvärdering av metoden.

A total of 153 cyclists were killed between 2007 and 2012, while more than 44,000 were so badly injured that they were admitted to A&E departments. 8,400 of the injured cyclists were seriously injured and 1,100 very seriously injured. Half the serious injuries are injuries to the arms and shoulders. About 90% of all cycling accidents in which cyclists are seriously injured happen in urban areas. Eight of every ten cyclists seriously injured sustained their injuries in single-bicycle accidents, and just over one-tenth in bicycle-motor vehicle accidents. The majority, 69%, of cyclists killed, lost their lives in collisions with motor vehicles, usually cars. Given what are judged to be the underlying causes of bicycle accidents, improved ice removal and winter tyres for bikes are considered to be the measures with the biggest potential for reducing the number of cyclists seriously injured, as well as the use of a cycle helmet and a protective jacket and trousers. Other important accident prevention measures are the removal of loose grit, good surface maintenance and adjusted kerbstones, followed by segregated cycle paths, safe bicycle crossings/overpasses and the removing of fixed objects on and beside the cycle path. Many serious injuries to cyclists can also be avoided by remedy deficiencies on the bicycle or its equipment. The most important measures for reducing the number of cyclist fatalities are increased helmet use and the prevention of collisions with motor vehicles or a reduction of the violence of such collisions by means of segregation, safe bicycle crossings/overpasses, emergency brakes and/or an external air bag on cars, and, for lorries, a warning system alerting drivers to the presence of cyclists in the “dead angle”. The analyses presented in this report were undertaken on behalf of the Swedish Transport Administration, and forms part of the work to devise a policy strategy for safe cycling.