Bus drivers often have irregular working hours and their work involve high levels of stress. These factors can lead to severe fatigue and the purpose of this study is to highlight how the working hours affect sleep, stress, fatigue and driving performance. The project includes four studies: questionnaire, sleep diaries and actigraphy, analyze of rosters and an experiment on real road with bus drivers. The hypotheses were that early morning shift, split shifts, long working hours and short hours of rest between shifts contribute to sleepiness, stress, fatigue and impaired driving performance, which together can result in increased safety. The overall results support these hypotheses. Generally, sleepiness and fatigue while driving are perceived as problems because drivers connect those factors with impaired driving performance, which increases the risk of incidents and accidents. In total 45 percent of all drivers had trouble at least twice a month to stay awake while driving and 19 percent had over the past decade been involved in an incident due fatigue. The experiment with split shift driving support these findings. The report concludes with a list of suggestions.

Förstärkt information vid övergångsställe, så kallade FIVÖ-system, är effektivt i termer av att öka fotgängares upplevelse av säkerhet och trygghet vid passage av övergångsstället. Syftet med föreliggande studie var att utvärdera effektiviteten av FIVÖ-systemen samt att fånga fotgängares, cyklisters och förbipasserande trafikanters uppfattning om de klassiska FIVÖ-systemen.

Studien omfattar en första genomgång av olyckor vid övergångsställen, hastighetsmätningar vid ett urval av platser samt intervjuer med fotgängare, cyklister och bilister som passerar FIVÖ-system. Resultaten visar att flest olyckor vid övergångsställen sker i tättbebyggt område i anslutning till korsningar på vägar där hastighetsbegränsningen är 50 kilometer i timmen. Detta speglar framför allt att det är där det finns övergångsställen. För urvalet av mätplatser visar resultaten av hastighetsmätningarna en signifikant lägre hastighet (~ 2,2 km/h) då FIVÖ-systemet var aktivt jämfört med då det inte finns ett system. Vidare visar resultaten att såväl fotgängare som cyklister upplever att systemen bidrar till att de är säkrare, känner sig trygga och att förbipasserande i större utsträckning stannar och släpper dem före. Bilisterna upplever att systemet bidrar till att de lättare kan upptäcka fotgängare och cyklister vid övergångsstället. Det finns dock en del utvecklingspotential avseende synbarheten. Såväl bilister som fotgängare och cyklister anser att de ljus som används vid testade FIVÖ-system kan förbättras och förstärkas.

From a traffic safety perspective it is highly motivated to define winter tires interms of their performance in icy road conditions. The present definition of winter(snow) tires, introduced in the EU in 2012, is based on packed snow performance.The present paper investigates the feasibility of an indoor winter tire classificationtest on ice. Results presented here indicates that a test procedure in an indoorhockey rink is possible, with relatively high repeatability. However, further fieldtest is required to fully establish feasibility of the procedure.

A Finite Element model of a generic Laboratory Seat was developed to replicate a physical counterpart used in rear-impact volunteer tests. The Laboratory Seat has a simplified design, developed to facilitate replication in computational models. The seat has a flat rigid base and the seatback consists of four horizontal panels attached to side posts by coil springs. The seat model was validated with results from component tests and sled tests, including the Anthropomorphic Test Device, BioRID II.

An initial test series was carried out to generate data for component validation: the first set of tests to characterise the coil spring properties; and the second set comprising Impactor Tests on Head Restraint Foam to assess the head restraint material properties.

For system level validation, sled tests were conducted both with the empty Laboratory Seat and with the BioRID II. The BioRID II tests were conducted in conjunction with an earlier volunteer test study.

Both the component and the sled tests were reproduced in a virtual environment. Good agreement was achieved between the mechanical tests and the computational simulations.

The seat model is freely available to use: https://openvt.eu/fem/open-access-laboratory-seat-model.

A literature review about the road safety effects associated with tires, rims and wheels was carried out, where the literature search was done in consultation with the VTI Library and information centre. The outcome resulted in approximately 90 different references, most of which refer to research articles in peer reviewed journals, but also some independent reports and books. A clear distinction was made with slip-related accidents related to winter conditions and different types of snow tires/tire characteristics not included in the study. Furthermore, only the type of accidents that occurs during vehicle operation was treated, which means that work accidents occurring during a service are not included in the study.

There is not much research published on the rim effect on road safety, and a U.S. accident investigator believes that the wheels generally are extremely reliable. Of the anomalies that can occur for the wheel as a whole, loosening of the wheel is the most serious. The studies that we found dealing with wheel imbalance only apply to comfort problems and increased road wear. Different wheel alignment will affect a vehicle's handling, but we have not found any study that has related this to road safety. For tires, we found no research on how different tire sizes and brands mounted on a vehicle affect its safety. Several studies show that there is a risk involved with mounting new tires on the front axle and worn tires on the rear axle. There is a consensus that during the replacement of two tires, the new tires should always be positioned on the rear axle, regardless if the vehicle is front or rear wheel driven. A number of studies show how the tread depth affects the wet grip during braking, and how the tires with less than 3 mm tread depth lose about half of the available friction compared to new tires.

In this study we have investigated how tyres with different road grip affect the stability of passenger cars equipped with Electronic Stability Control (ESC) systems during winter road conditions. A field test with a double lane change manoeuvre on ice was performed using 6 test drivers, 4 different passenger cars and 4 different studless winter tyres. The specific tyres were chosen to represent a large difference of road grip on ice and snow. The results show that there was a large performance difference between the best and worst tyres with ESC off, and that activating ESC only resulted in a minor increase of performance.

Traffic accidents during winter time are to a larger extent categorized by loss of vehicle control resulting in a skidding accident, compared to accidents occurring summer time. In a study by the Swedish Transport Administration, it was shown that for fatal accidents happening winter time, skidding had occurred in 64 per cent of the accidents on winter road conditions. Out of these, 82 per cent were so called over steering accidents, i.e. events where the vehicle starts to spin.

The purpose of this study was to develop av method for testing a vehicle's stability during oversteering on slippery roadways, and to use this method to test how large the difference is between different kinds of winter tyres on ice and snow.

A test method based on NTHSA's sine-with-dwell manoueuvre was developed. The manouevre uses a steering robot and induces heavy oversteering on slippery surfaces, such as ice and snow.

The manouevre was then used with an ESC equipped rear-wheel driven passenger car, fitted with both new and worn winter tyres of the three different kinds that are available in Sweden, to compare the level of oversteering that is possible to obtain with a steering manouevre on different ice and snow surfaces. The results show that studded tyres are more stable than unstudded on smooth ice. Even the worn studded tyre, with only a fraction of the studs remaining, is performing well compared to the unstudded tyres, and is comparable to a new unstudded winter tyre of Nordic type and much better than the tyres of Central European type. The winter tyres of Central European type stand out as those generating most oversteering on this surface. On surfaces with higher friction level, the tyres with least grip are also those that generate least oversteering, which makes it difficult to discuss these results in terms of traffic safety.

Fatal accidents during winter time in Sweden are to a large extent due to vehicle spinning. Therefore, it is crucial to analyse and compare vehicle/tyre performance on slippery roads with respect to oversteering. In this study, a new test method for evaluation of vehicle's stability during oversteering on icy roadways is developed and evaluated using a series of tests with a rear wheel driven car, equipped with ESC, and six different tyres on ice test tracks in northern Sweden. The test method consists of an asymmetric sine-with-dwell manoeuvre and a measure forquantifying the level of oversteering based on the relation between yaw rate and lateral acceleration. The test results show good robustness of the method, and that it can successfully rate the various tyres performance on polished ice. However, to have a fair comparison, the proposed method should be modified to take into account the steering ability of the tyres and the consequent difference in the manoeuvre severity when tested with tyres with different side grip.

In Sweden non-studded winter tyres has become increasingly popular during the winter season. Since it is allowed to use non-studded winter tyres also during summer time, a large number of drivers choose to do that. The purpose of this study has been to investigate the difference in road grip between winter- and summer tyres summer time, and to assess possible effects on traffic safety. A field test was carried out where road grip was measured on dry and wet asphalt pavement with different types of tyres. The results showed that the winter tyres (non-studded of Nordic type) led to 15–20 per cent longer braking distances compared to summer tyres. Accident risk analyses were performed for three types of accidents: rear end collision, frontal collision and collision with pedestrian. The study indicated that using winter tyres leads to an increase in accident risk for all three accident types. At low collision speeds the absolute increase in risk is small, maybe just a few percent, but the relative increase may be large, sometimes up to 100 per cent. In-depth studies of fatal accidents indicated a 3 per cent increase of risk from using winter tyres summertime, compared to summer tyres. However, this result was not statistically significant.

The aim of this study has been to develop new Seat Evaluation Tools (SET)s with the geometries of an average female (50F) and male (50M) as seated car occupants, based on data from humanshape.org. The SETs have been designed to evaluate the occupant protection performances of car seats in a low severity rear impact.

Focus areas have been the motion of the spine, neck and shoulders to enable a human-like interaction with the car seat. Improvements have been made to previous designs of the neck spring and damper system, and a new solution for shoulder flexibility has been implemented. Soft body materials have been used to facilitate the motion of the torso, and a 3D thoracic and lumbar spine design has been developed.

Two physical prototypes, SET v0.1 50F and 50M, have been developed and all drawings and CAD models have been made available under open-source license on the OpenVT platform (https://openvt.eu/). The prototypes have been run in initial dynamic tests and the results have been compared to previous volunteer tests.

This work was carried out within the EU-funded project, VIRTUAL.

Projektet, som är en pilotstudie, syftade till att undersöka effekten av låsningsfria bromsar, ABS, på cykel. Fråga som projektet syftade till att besvara: Kan cyklars stabilitet under inbromsning förbättras av låsningsfri broms (ABS) på framhjulet? Frågan söks besvaras genom utformning och genomförande av bromsprov av cykel med och utan ABS. Cykelolyckor är bland de vanligaste orsakerna till trafikskador i Sverige, ofta med svåra skador och medicinsk invaliditet som följd. Närmare hälften av alla svårare trafikskador har uppstått på grund av cykelolyckor. ABS-bromsar har visats reducera risken för skada för motorcyklister genom ökad stabilitet och därmed minskad risk för omkullkörning i samband med bromsning. Däremot finns begränsad kunskap om effekten för cyklister. Två Crescentcyklar med sluten ram (herrcykel) testades: en konventionell, bakhjulsdriven modell med v-broms (fäljbroms) på framhjulet och en framhjulsdriven modell med el-assistans och navbroms i framhjulet. Med den konventionella cykeln utfördes två typer av tester, med och utan ABS-bromsar. ABS-bromsen var av modellen SABS V1. På el-cykeln med navbroms justerades bromsverkan så att framhjulet ej låstes, jämfört med full bromsverkan. En Hybrid II krockdocka, 50-percentil man, användes som cyklist i proven. Proven utfördes vid hastigheterna 17 och 20 km/h. Cyklarna bromsades maximalt på framhjulet. Friktionen var ungefär 0,7–0,8. Resultaten visade att ABS på cykelns framhjul gör att framhjulet inte låses vid full inbromsning och bakhjulet behåller kontakten med underlaget. Vid prov med v-broms eller navbroms med full broms-verkan blev bromssträckan cirka 2 meter, men framhjulet låstes vid full broms och bakhjulet lyfte från underlaget. Det innebar att cykeln då endast balanserade på framhjulet. Prov med ABS-broms på v-bromsen och justerad bromsverkan på navbromsen resulterade däremot i inbromsning utan låsning av framhjulet. Bromssträckan var i dessa prov cirka 4 meter. Resultaten var liknande för de båda cyklarna.

Increased knowledge is needed on how to handle cyclists in work zones to reduce the risk of crashesand increase accessibility. This project has aimed to provide a basis for requirements on the design and use of temporary traffic control devices adapted for cyclists and for regulations, guidelines and education regarding the handling of cyclists in work zones. In addition to accident analyses and literature reviews, three different empirical studies have been carried out: about 50 simulated single bicycle crashes in the VTI crash safety laboratory with different road equipment at different crashangles; studies with recruited cyclists on the VTI cycle test track where different widths of passages and speed-reducing measures were evaluated, and in a real traffic environment, where visibility and clarity were studied by varying the size and location of road signs. The results show that since 2016, more than 200 cyclists have been injured at road works, of which 40 were seriously injured – 9 out of 10 in a single bicycle crash. With high bicycle flows and narrow passages, road works contribute to increased complexity and an increased frequency of collisions. Temporary access routes for cyclists within the construction zone are preferable to longer detours around the construction site, and they should be self-explanatory and at least 2.5 meters wide with an even and clean surface. The amount of road equipment should be minimized as it takes up space, attention and can injure cyclists. Barriers to prevent a cyclist from falling into a shaft need to be 1.4 meters high or equipped with energy-absorbing “catch nets”. By consistently using small sized and correct road signs with the correctmessage, clarity is created that makes it easier for cyclists to follow the rules and “behave correctly”. 

In this project, single bicycle crashes have been simulated in the VTI crash safety laboratory. Crash tests including bicycles are scarce and when performed they usually simulate collisions with motor vehicles, although earlier studies have shown that cyclists are more frequently injured in single bicycle crashes. The objective of this study was to examine the influence of bicycle design and speed on the head impact when suffering from a single bicycle crash, and the possibility to study this using crash tests. In order to do that, two bicycle crash scenarios were simulated: “a sudden stop” and “sideways dislocation of the front wheel”; using four different bicycle types: a “lady’s bicycle”, a commuter bicycle, a recumbent and a pedelec; at two speeds: 15 and 25 kilometer per hour. In addition, sideway falls were performed with a bicycle standing still. All tests were done with a Hybrid II 50 percentile crash test dummy, with acceleration measurements in the head, placed in the saddle of the bicycles.

Objective: The objective of this study was to examine the influence of bicycle design and speed on the head impact when suffering from a single-bicycle crash, and the possibility to study this using crash tests.

Methods: Simulations of single-bicycle crashes were performed in the VTI crash safety laboratory. Two bicycle crash scenarios were simulated: "a sudden stop" and "sideways dislocation of the front wheel"; using four different bicycle types: a "lady's bicycle", a commuter bicycle, a recumbent bicycle and a pedelec; at two speeds: 15 and 25 km/h. In addition, sideway falls were performed with the bicycles standing still. All tests were done with a Hybrid II 50(th) percentile crash test dummy placed in the saddle of the bicycles, with acceleration measurements in the head.

Results: The crash tests showed that a sudden stop, e.g. a stick or bag in the front wheel, will result in a falling motion over the handle bars causing a forceful head impact while a sideways dislocation of the front wheel will result in a falling motion to the side causing a more moderate head impact. The falling motion varies between the different bicycle types depending on crash test scenario and speed. The pedelec had a clearly different falling motion from the other bicycle types, especially at a sudden stop.

Conclusions: The study implies that it is possible to examine single-bicycle crashes using crash tests, even though the setup is sensitive to minor input differences and the random variation in the resulting head impact values can be large. Sideway falls with the bicycles standing still were easier to perform with a good repeatability and indicated an influence of seating height on the head impact.

In Sweden there is an on-going process to formulate a national standard regulating the design of temporary traffic control devices used on pedestrian and bicycle paths. This paper presents results from simulated single-bicycle crashes with the purpose to create an understanding of how different features of such devices affect the risk of injuries among cyclists. A Hybrid II 50th percentile crash test dummy was placed in the saddle of a bicycle and crash tests, usually at 25 km/h, were performed. Eleven different types of road equipment were included, and different crash angles were applied, in a total of over 50 crash tests. The road equipment represented temporary traffic control devices of various kind commonly used in Sweden, but also some specifically designed for cyclists. The tests were documented with several video cameras at different angles. Slow motion pictures were analyzed with focus on mechanisms during impact and the following motion of the bicycle and the dummy. Observations regarding “body parts” in contact with the road equipment were of particular interest highlighting design features of importance such as height, smoothness of surfaces and energy-absorbing capacity. The tests show that all bicycle crashes into road equipment can cause injuries and thus the use of work zone material on bicycle paths should be avoided, if possible. Safety barriers designated to prevent cyclists from falling into a shaft must be high enough to do so and be anchored and linked together correctly to prevent them from falling and creating dangerous situations. Temporary traffic control devices should be flexible or energy-absorbing to moderate the injury outcome of a potential bicycle crash. Fences should have a fine meshed net construction to prevent bicycle handlebars from getting stuck. All road equipment should be designed without sharp edges as they could cause injuries to cyclists passing or crashing into the equipment.

Det som brukar kallas den svenska modellen för barn i bil, innebär att barn i Sverige rekommenderas att färdas i bakåtvänd bilbarnstol upp till en ålder av 4-5 år. En stark bakomliggande orsak till denna rekommendation är att risken för att barn dödas eller allvarligt skadas är fem gånger större vid framåtvänt åkande än vid bakåtvänt åkande. I Sverige försvann i maj 2008 möjlighet till provning och godkännande enligt VVFS 2003:29 Bilaga 2, det som i allmänhet kom att kallas för T-märkning. Denna provningsmetod bedömdes vid införandet 1975 kunna mäta relevanta nivåer för bl a nackkrafter. I Sverige infördes 1981 ECE R44 som provningsmetod och godkännandemärkning för bilbarnstolar. ECE R44 saknar mätning av nackkrafter. P g a avsaknaden av möjligheten till mätning av nackrafter i ECE R44 fortsatte provning och märkning enligt metoden för T-godkännande. Dessa två provningsmetoder bedömdes tillsammans kunna borga för bra bakåtvända bilbarnstolar, varför det på svenska marknaden förekom relativt många bilbarnstolar som var dubbelmärkta d v s både med ECE R44 och T-märkning.

Förutom avsaknaden av möjlighet för T-märkning är ytterligare en negativ företeelse att Sverige i allt större utsträckning bedöms påverkas av den i Europa vanliga företeelsen, att vända barnen framåtvänt långt tidigare än vid 4-5 års ålder. Mot bakgrund av detta bedömdes det att en metod för frivilligmärkning skulle utarbetas. Metoden skulle använda den svenska T-märkningen som utgångspunkt. Naturligtvis skulle även tas i beaktande att T-märkning utformades i mitten av 70-talet, och inga genomgripande revisioner har skett genom åren. Frivilligmärkning skall genomsyras av det svenska synsättet på hur barn bör skyddas i bil- barnstolar. Avsikten var dessutom att alla tre inblandade huvudparter i en bilbarnstol, skall påverkas positivt av frivilligmärkning. Med tre huvudparter menas barnet som sitter i bil- bilbarnstolen, konsumenten som skall montera och använda bilbarnstolen samt tillverkaren av bilbarnstolen. Utöver detta skall namnet och symbolen på frivilligmärkning så långt som möjligt, vara ”självförklarande” både för de konsumenter som förstår svenska och för dem som inte gör det.

This is an overview of the field of electric driven vehicles, aiming to give an overview of the introduction of vehicles and supporting the development of the vehicle electrification. Some current technical solutions are presented, and a possible future is outlined, in the field of vehicles, batteries as well as infrastructure and power supply solutions. A brief overview of the system perspective on society, drivers and vehicles and the impact on the environment is given. Some electrification initiatives, realized or planned, are described with a major focus on the Swedish market, although a brief international view is presented. Governmental electrification targets and duly support is presented, as well as some examples of current research in this field. For this document, the electric vehicle is mainly to be understood as a passenger type vehicle with some type of electric power supply. Initially presented are various types of electric vehicles, EV, such as (pure) electric vehicles (with no alternative power), electric hybrid vehicles, plug-in (chargeable) hybrid vehicles and fuel cell vehicles. On the 30th of April 2014 there were 3714 vehicles named “plug-in” hybrid, with an option of external charging, registered in Sweden. Out of those there were 1 260 only electric powered and 2454 of the type chargeable hybrid vehicles. The most common battery type in the modern EV is the lithiumion accumulator. EV normally retain a high purchase price, mainly due to the cost of the batteries. The sustainability of the batteries will affect the overall cost. Second hand value is still very uncertain, as well as an uncertainty by the users about the EV functionality, i.e. the possibility to drive a certain distance. An often raised question is the lack of external vehicle noise, possibly making the EV a potential risk due to low hearing detectability. To be able to use an EV, batteries need to be charged. A survey by Transport Analysis (Sweden) shows that 70% of all transportation made by passenger vehicles in Sweden are shorter than 30 km, with the implication that most of these travels are well suited to be performed by an EV. In the report various solutions to the charging of batteries are presented and whether and how power could be supplied.

Passive safety testing has been based on accident research where objective physical evidence can be compiled and analysed when establishing technical test requirements. Active safety tests pose new challenges because objective data is more difficult to obtain. Until pre-crash variables became available in Event Data Recorders (EDR), the only sources of pre-crash vehicle motions were tire marks or witness statements. Both data sources have limitations since they may not always be available and require interpretation by the analyst. The pre-crash EDR data variables provide an objective source of data to active safety test development. However, the suitability of the data has not been thoroughly investigated in the published literature.

The review of existing data shows that the variables identified in the new EDR requirement in FMVSS 563 are useful but incomplete for a comprehensive analysis of vehicle dynamics manoeuvres prior to a crash. In particular, the absence of vehicle yaw rate reduces the positioning accuracy of the vehicle in reconstructions. The objective data in the limited cases were used to compile the frequency of pre-crash braking and steering, and when possible, the magnitude of these driver inputs. Active Safety test development will benefit with more EDR analysis but the older data that does not conform to Part 563 has limited application.

The Plus Test is a well reputable voluntary crash test carried out by VTI. It was born in 2009 as a complement to the standard approval for child restraint systems ECE R44. Since the standard approval did not include limits for neck forces. In 2013 a new regulation for approval for child restraint systems was introduced called UNECE R129. The standard included updated test rigs and more biomimetic crash test dummies among other things. As a result of the more sophisticated standard child restraint systems became more advanced but the measurement of neck forces only to be monitored. To accommodate the new development of child restraints VTI saw the need of renewing the Plus Test. The voluntary Plus Test is still permeated by the Swedish model. Which is that young children should travel rearward facing for as long as possible, at least until the age of five. The goal with the renewal is to promote the principle of even load over the whole-body supporting head and torso equally in a frontal collision. A new Plus Test has been introduced 2023, with new dummies, new sled, and new limit values for approvals. Basis for the renewal has been literature, analyses of existing data, computer simulations and crash tests. 

This study aims to enhance knowledge of impact-friendly, resilient or yielding lighting columns. The project incorporates an international literature review, followed by an enhanced view of utility for Swedish society by the selection and use of resilient lighting columns. Finally, an accident study of lighting columns is included.

Results from the literature study show an earlier and more frequent use of resilient lighting columns in the Nordic countries and the USA than for example Great Britain. Passively safe and resilient columns should be used in order to reduce injury risk. It is a main recommendation to primarily remove objects of obvious danger from the roadside environment, and when impossible use some type of passively safe resilient or yielding road equipment instead. Cost benefit analyses in several countries have shown a positive traffic safety result for passively safe columns, except for roads with very low traffic volume or low speed.

The accident study, based on 6 000 injured persons, shows that on the rural state road network, most of the column collisions occur on roads with speed limit 70 kilometer per hour (35%), followed by 50 kilometer per hour (25%). On urban municipality roads, most accidents occur at speed limit 50 kilometer per hour (58%), followed by 70 kilometer per hour (13%).

TMAs (Truck Mounted Attenuator) are used as mobile protectors for road work zones. They are typically mounted on trucks. In this project the VTI has crashtested TMAs installed on alternative TMA carriers, i.e. a tractor and an articulated front-end loader. Later on, the project was enhanced with an additional crash test on a steel frame intended for transportation on trucks and, in cooperation with Autoliv, a further crash test where the risk of whiplash injuries was to be studied. The latter was done by repeating the crash test with a TMA on a tractor and having a BioRID crash test dummy in the driver seat. The test was run according to NCHRPR 350 3-52 procedure. In an external elongation of the project, sled tests were run at Autoliv; the results are included in this report as an annex.

Projektet går ut på att ta fram en matris för längsgående barriärer vid vägarbeten där den faktiska hastigheten är en annan än vid testtillfället. Med tunga skydd menas det barriärer av t.ex. typ GP-link. Bakgrunden är att det idag saknas en samlad kunskap om hur tunga skydd fungerar i verklig hastighet och där miljön är av sådan karraktär att de W-mått som anges vid testtillfällena inte kan uppbringas. Dessutom får just tunga skydd flest röda anmärkningar vid Trafikverkets kontroller på vägarbetsplatser och det är då främst att det angivna W-måttet inte följs. Frågeställningar som bland annat kommer att undersökas är:

• Hur klarar sig barriären vid olika vinklar
• Hur klarar sig barriären vid olika hastigheter?
• I vilken utsträckning förändras W-måttet?

Background; Trafikverket (the Swedish Transport Administration) was asking for enhanced information about interaction between soil grading, bearing capacity and type approved vehicle restraints systems.

Purpose: To get enhanced knowledge about interaction between soil grading, bearing capacity and type approved vehicle restraints systems.

Method: Dynamic testing with an impact sled, some static push/pull tests and finally some full-scale crash testing with a passenger car into a barrier.

Results: Barrier posts should not have a shorter length below ground level than 1.0 meter. A slope shoulder behind a barrier installation should not be arranged closer than 0.6 meter behind the same. In soil with less bearing capacity or compact ability it is probably possible to enhance barrier functionality by using even longer barrier posts, with a larger proportion of the post being inserted into ground.

In the majority of the investigated accidents, the motorcyclist is still riding his bike while hitting the barrier. A substantial part of the accidents take place on straight roads. In the most severe fatal accidents, the motorcyclist is caught by the barrier. Most common are of course injuries to legs and feet, but severe head, chest and body injuries are found in the fatal accident cases too.

The barrier posts are of great influence in most accidents. Based on the observed accidents, Sweden ought to reduce the use of barriers where parts of the posts face the traffic in front of the longitudinal cross railing member of the barrier, regardless of what is stipulated in EN1317-2 and draft EN1317-8. By the same judgment, posts protruding above the horizontal cross railing member or otherwise exposing sharp top edges ought to be, from a crash safety point of view, banned.

Any MPS fulfilling the requirements of the draft EN1317-8, soon to be on "CEN technical enquiry", would most certainly not alter the outcome of any of the investigated accidents.

In total 15 accidents are reported, of those 7 fatal. Concerning wire rope barriers we have detected 7 accidents, 2 of them fatal. On beam barriers 5 accidents are recorded, of them 3 fatal. Or 2 fatalities, if another disease is allowed to be removed from the overall counting. One accident is on a concrete median barrier, and it is most probably not the barrier that causes the fatality but the lighting column mounted on top of the barrier. Of the 15 accidents, 12 are on EN1317-2-approved barrier types. In two cases the motorcyclist is intoxicated by alcohol.

Four side-on crash tests have been run, aiming at studying the crash safety of the combination of personal by worn police equipment and side-on crash protection in modern cars. The four tests involved a policeman (dummy) with and without personal equipment in a driving position in a vehicle with and without side-on crash protection.

Very short, it can be said that the performed tests do not show any conflict between side-on crash protection in cars and the equipment worn on the uniform, but the fact that some police equipment is stiff, hard and angular increases the injury risk, however, not quantified in these tests.

From a more strict crash safety perspective, most of the tested police-related equipment such as truncheon, weapon and radio are stiff and voluminous. Regardless of the viewpoint of operational police work or durability, the backsides of the weapon and truncheon holsters etc. could be much smoother and more energy absorbing, resulting in a far lesser injury risk in the event of a traffic accident.

In a closing discussion of this document there are some suggestions for measures, together with a loose discussion about injury risk. Some of the points are: - Information. - Placement of equipment. - Possible future adjustments of the uniform in respect of incorporated crash protection over the hip.- Possible future adjustments of car seats and/or car door interior panels.

Fractures to the hip area seem to be the injury with the closest connection between police equipment and side-on collisions.