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Thomson, Robert
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Publications (10 of 11) Show all publications
Adolph, T., Eggers, A., Thomson, R. W. & Mizuno, K. (2014). Comparison of the dummy response in two different restraint system crash tests. In: 2014 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury: . Paper presented at International Research Council on the Biomechanics of Injury Conference, IRCOBI 2014, 10 September 2014 through 12 September 2014 (pp. 545-561).
Open this publication in new window or tab >>Comparison of the dummy response in two different restraint system crash tests
2014 (English)In: 2014 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury, 2014, p. 545-561Conference paper, Published paper (Refereed)
Abstract [en]

In the European Project FIMCAR, a proposal for a frontal impact test configuration was developed which included an additional full width deformable barrier (FWDB) test. Motivation for the deformable element was partly to measure structural forces as well as to produce a severe crash pulse different from that in the offset test. The objective of this study was to analyse the safety performance of vehicles:

  • in the full width rigid barrier test (FWRB) and
  • in the full width deformable barrier test (FWDB)

In total, 12 vehicles were crashed in both configurations. Comparison of these tests to real world accident data was used to identify the crash barrier most representative of real world crashes. For all vehicles, the airbag visible times were later in the FWDB configuration. This was attributed to the attenuation of the initial acceleration peak, observed in FWRB tests, by the addition of the deformable element. These findings were in alignment with airbag triggering times seen in real world crash data. Also, the dummy loadings were slightly worse in FWDB compared to FWRB tests, which is possibly linked to the airbag firing and a more realistic loading of the vehicle crash structures in the FWDB configuration. Evaluations of the lower extremities have shown a general increasing of the tibia index with the crash pulse severity.

Keywords
Anthropometric dummy, Behaviour, Impact test (veh), Front, Air bag (restraint system), Crash barrier, Deformable barrier (impact test)
National Category
Vehicle Engineering
Research subject
90 Road: Vehicles and vehicle technology, 913 Road: Vehicle interior safety; 30 Road: Highway design, 34 Road: Safety devices
Identifiers
urn:nbn:se:vti:diva-9373 (URN)2-s2.0-84915822592 (Scopus ID)
Conference
International Research Council on the Biomechanics of Injury Conference, IRCOBI 2014, 10 September 2014 through 12 September 2014
Available from: 2016-04-13 Created: 2016-03-02 Last updated: 2016-04-25Bibliographically approved
Adolph, T., Schwedhelm, H., Lazaro, I., Versmissen, T., Edwards, M., Thomson, R. & Johannsen, H. (2014). Development of compatibility assessments for full-width and offset frontal impact test procedures in FIMCAR. International Journal of Crashworthiness, 19(4), 414-430
Open this publication in new window or tab >>Development of compatibility assessments for full-width and offset frontal impact test procedures in FIMCAR
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2014 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 19, no 4, p. 414-430Article in journal (Refereed) Published
Abstract [en]

The goal of the project FIMCAR (Frontal Impact and Compatibility Assessment Research) was to define an integrated set of test procedures and associated metrics to assess a vehicle's frontal impact protection, which includes self-And partner-protection. For the development of the set, two different full-width tests (full-width deformable barrier [FWDB] test, full-width rigid barrier test) and three different offset tests (offset deformable barrier [ODB] test, progressive deformable barrier [PDB] test, moveable deformable barrier with the PDB barrier face [MPDB] test) have been investigated. Different compatibility assessment procedures were analysed and metrics for assessing structural interaction (structural alignment, vertical and horizontal load spreading) as well as several promising metrics for the PDB/MPDB barrier were developed.The final assessment approach consists of a combination of the most suitable full-width and offset tests. For the full-width test (FWDB), a metric was developed to address structural alignment based on load cell wall information in the first 40 ms of the test. For the offset test (ODB), the existing ECE R94 was chosen. Within the paper, an overview of the final assessment approach for the frontal impact test procedures and their development is given.

Keywords
Impact test (crash), Head on collision, Car, Protection, Evaluation (assessment), Specifications
National Category
Vehicle Engineering
Research subject
90 Road: Vehicles and vehicle technology, 91 Road: Vehicle design and construction
Identifiers
urn:nbn:se:vti:diva-9330 (URN)10.1080/13588265.2014.909562 (DOI)000337562900008 ()2-s2.0-84901635169 (Scopus ID)
Available from: 2019-05-21 Created: 2019-05-21 Last updated: 2019-09-30Bibliographically approved
Wisch, M., Ott, J., Thomson, R., Léost, Y., Abert, M. & Yao, J. (2014). Recommendations and Guidelines for Battery Crash Safety and Post-Crash Safe Handling.
Open this publication in new window or tab >>Recommendations and Guidelines for Battery Crash Safety and Post-Crash Safe Handling
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2014 (English)Report (Other academic)
Abstract [en]

Electric vehicles (EV) present a research challenge for safety engineers. These vehicles are designed using conventional vehicle design strategies but do not contain conventional materials or structures. Accident analyses cannot be conducted until sufficient EVs are involved in a crash and are reported in crash databases. Until such data exists, researchers must use other research methods to understand and predict potential problems.

The passive safety activities in the EVERSAFE project used conventional accident analysis, computer simulation, physical testing, and literature reviews to get a better understanding of the issues for EV and their battery systems. Based on current practice, Lithium-ion (Li-ion) batteries are the main chemistry that should be explored and pouch type cells are the most vulnerable for damage.

Conventional vehicles were used in EVERSAFE as a surrogate for EVs to identify expected deformation and acceleration loads from real crashes. Based on available information and previous compatibility research, the main issue that arose was that for small vehicles. These vehicles experience the highest accelerations in car-car crashes and even some fixed barrier crashes. Except for a handful of cases, there was not enough data to confirm that EVs have a higher injury or fire risk than similar conventional vehicles.

Chemical analyses of the battery components identified the potential processes that can lead to emissions of flammable or toxic gases. These chemicals develop when the battery temperatures are too high and can develop if mechanical loading causes an internal short circuit or an external heat source affects the battery. There are several harmful chemicals contained in battery electrolytes and hydrofluoric acid (HF) appears to be the most relevant gas to monitor.

Simulation activities in EVERSAFE have developed new battery models and an effective methodology to assess worst case loading in a battery was also developed. The models were used to explore both local cell-level deformations as well as whole vehicle crash performance. The simulations confirmed the ability of ductile structures to protect the battery and at the same time identify the risks created when the battery pack structures start to deform and result in crushing of the cell structures.

Component tests of the battery cells demonstrated that the pouch cell can be quite resilient to shear and penetration loads. They are more sensitivity to crushing loads and the ductile plastic structures in the battery can be a useful safety element. This information underlines the need to maintain the battery in an undeformed part of the vehicle.

Full scale crash tests demonstrated safe battery performance even for more severe tests than those the vehicle are required to meet. Both a side impact and a rear/front multiple impact could not provoke thermal activity or hazardous emissions from the battery in a Mitsubishi iMiEV or a BMW i3. These results can be used to promote consumer trust in the technologies.

A complementary part of the study was to determine what procedures and equipment are needed for rescue services if they attend a crash with an EV. There appears to be no fundamental changes in the rescue approach at a crash scene. There is a need for better support for rescue services to identify the type of energy source (internal combustion, electric, or both) of a given vehicle. There are some actions needed for an EV that must be considered when attending a crash and these can only be done when the vehicle is known to be an EV. eCall is one tool that can facilitate the identification of EVs as well as update the status of the battery to the rescue services. Rescue sheets are being developed in ISO committees and these need to be made available in standard and secure locations in a vehicle. There is the potential for fire and toxic gas and a firefighter must be able to identify the appropriate type of safety equipment to wear. Knowledge of the chemical processes that

can occur in a battery is important. It is more important that firefighters have access to methods that

identify risk of fire or chemical hazards. Thermal imaging cameras and portable gas detectors,

already available on rescue vehicles, may be sufficient for monitoring EVs at a crash site.

Publisher
p. 99
Series
EverSafe ; D3.1
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:vti:diva-14297 (URN)
Projects
EverSafe
Available from: 2019-11-05 Created: 2019-11-05 Last updated: 2019-11-05Bibliographically approved
Thomson, R. (2014). Recommendations for New Safety Requirements and Research.
Open this publication in new window or tab >>Recommendations for New Safety Requirements and Research
2014 (English)Report (Other academic)
Abstract [en]

The main objective of EVERSAFE is to facilitate integration of electrical vehicles (EVs) into European vehicle traffic. The performance and control characteristics of electric machines also offer more opportunities for vehicle designs and systems that benefit segments of the population, an example being semi-automated vehicles that provide mobility to an aging population. There are many opportunities for a strong market value of European vehicle manufacturers that can be exported worldwide.

Customer acceptance increases when EV safety is guaranteed for normal operation or an accident. The consequences of a negative image for EVs are considerable and will limit the development and penetration of a new vehicle type that can have financial, environmental, and social benefits for Europe. The EVERSAFE project had three main areas of research to ensure a robust market for EVs:

  1. The perceptions of electric vehicles from a user point of view
  2. Investigations of vehicle safety encompassing both active and passive vehicle safety implications that are part of the vehicle’s design
  3. Developing guidelines and recommendations for post-crash handling of electric vehicles that are not addressed in the practice for conventional (internal combustion) drivelines

The research plan was developed to identify the most high risk scenarios, investigate their potential consequences, and identify any corrective actions in terms of further research, industry standards, or government regulations.

The project used focus groups of consumers to identify perceived issues as well as expert judgement to identify specific research cases. Building on accident analysis, critical load cases for investigation for both active and passive safety were identified. Lateral and longitudinal load conditions for the vehicle were identified. For active safety the longitudinal case of interest was regenerative braking and yaw stability due to wheel hub motor failure on one wheel was the lateral case. Passive safety research was focused on pole side impacts for the lateral load case and rear end crashes for the longitudinal case. Post-crash handling of vehicles with electric drive trains was also identified as an area for investigation.

The main findings of the active safety investigations suggested that the potential failures for regenerative braking and wheel hub motors could be compensated by the drivers. Volunteer drivers participated in controlled studies in a driving simulator and a modified vehicle. For the investigated controlled cases there were no major safety issues identified, however the cases were not in real traffic and did not present complex traffic threats.

Passive safety investigations used component tests of battery cells, full scale crash tests, and numerical simulations to study the risks during a crash. The tested cells and vehicle crash tests demonstrated good safety levels. The simulations and component tests were useful to identify that the main risk for vehicles is crushing the battery pack and battery modules.

The safe handling of electric vehicles after a crash requires updates to the conventional rescue operations. The main issue is to identify when an electric vehicle is involved in a crash and to ensure the high voltage system is disconnected and preferably neutralized.

The results of the EVERSAFE project indicate that the general level of EV safety is quite high and that no critical safety issues have been identified. There are areas where the industry should develop universal standards to improve the driver interaction with the new EV systems and minimise the risk of crashes due to inappropriate driver expectations. When a crash with an EV occurs there appears to be little chance for fire or the emission of toxic substances, but there needs to be more work to assist the firefighters in identifying EVs, disconnecting electrical systems, and possibly neutralizing batteries after a crash.

Improving safety for the road user is an ongoing process and EVERSAFE has recommendations to further improve the good level of safety of the existing vehicle fleet. The results of EVERSAFE indicate that current and potential owners of vehicles with electric drivetrains should not consider these vehicles as less safe than vehicles with conventional (internal combustion) drivetrains.

Publisher
p. 17
Series
EverSafe ; D4.2
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:vti:diva-14299 (URN)
Projects
EverSafe
Available from: 2019-11-05 Created: 2019-11-05 Last updated: 2019-11-05Bibliographically approved
Thomson, R. W., Sandin, J., Bagdadi, O., Hjort, M., Augusto, B. & Andersson, H. (2013). EDR Pre-Crash Data: Potential For Applications In Active Safety Testing. In: Proceedings of the 23rd International Technical Conference on the Enhanced Safety of Vehicles, May 2013, Seoul: . Paper presented at 23rd International Technical Conference on the Enhanced Safety of Vehicles, May 2013, Seoul. , Article ID 13-0414.
Open this publication in new window or tab >>EDR Pre-Crash Data: Potential For Applications In Active Safety Testing
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2013 (English)In: Proceedings of the 23rd International Technical Conference on the Enhanced Safety of Vehicles, May 2013, Seoul, 2013, article id 13-0414Conference paper, Published paper (Refereed)
Abstract [en]

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.

Keywords
Accident, Characteristics, Collision, Data acquisition, Dynamics, Vehicle handling
National Category
Applied Mechanics
Research subject
80 Road: Traffic safety and accidents; 90 Road: Vehicles and vehicle technology
Identifiers
urn:nbn:se:vti:diva-7093 (URN)
External cooperation:
Conference
23rd International Technical Conference on the Enhanced Safety of Vehicles, May 2013, Seoul
Available from: 2014-09-16 Created: 2014-09-16 Last updated: 2016-08-30Bibliographically approved
Linder, A., Thomson, R., Svensson, M., Carlsson, A., Lemmen, P., Schmitt, K.-U. & Tomasch, E. (2013). Occupant diversity in modelling and evaluation related to soft tissue neck injuries in low severity impact. In: Proceedings of the 16th International Conference Road Safety on Four Continents: Beijing, China. 15-17 May 2013. Paper presented at 16th International Conference Road Safety on Four Continents. Beijing, China (RS4C 2013). 15-17 May 2013. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Occupant diversity in modelling and evaluation related to soft tissue neck injuries in low severity impact
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2013 (English)In: Proceedings of the 16th International Conference Road Safety on Four Continents: Beijing, China. 15-17 May 2013, Linköping: Statens väg- och transportforskningsinstitut, 2013Conference paper, Published paper (Other academic)
Abstract [en]

It is well established that the risk of soft tissue neck injuries (or whiplash associated disorders) is higher for females than for males, even in similar crash conditions. Injury statistics from the mid 1960´s until today all show that females have a higher risk of sustaining such injury than males, ranging from 1.5 to 3 times higher. These injuries arise in one of the most frequent collision types and thus an important societal issue.

Testing and evaluation of automotive systems are essentially determined by crash test dummies representing the 50th percentile male crash test dummy. While this dummy corresponds to a 90th -95th percentile female with regards to stature and mass, it may not be applicable for assessing the biomechanics of females, particularly for injuries resulting from low velocities rear impacts. Females and males have different anthropometry and mass distributions which may influence the interaction of the upper body with the seat backrest and head restraint and thus the injury risk.

In this study the anthropometry and mass distribution of an average female was established. The anthropometry of the 50th percentile female for a rear impact crash dummy model was derived from data published in the scientific literature and data available to the consortium. This data was used to develop a finite element model of an average female dummy EvaRID (Eva – Female, RID – Rear Impact Dummy) and a new loading device called BioRID 50F. Both the numerical and physical models were based on the currently available rear impact dummy of an average male, the Biofidelic Rear Impact Dummy (BioRID) II.

Volunteer tests involving male and female subjects were performed. Analysis of the volunteer tests resulted in dynamic response corridors that were used in the evaluation of the EvaRID model. Initial evaluations of seat performance were also undertaken with the male and female versions of the BioRID II physical test devices. The results show how the design of the seats are sensitive to the occupant mass distributions and, in some cases, resulted in poorer performance when loaded with a smaller and lighter dummy model. Future safety evaluations need to be adjusted to account for different occupant size and gender.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2013
Keywords
Neck, Injury, Vehicle occupant, Variability, Anthropometric dummy, Female
National Category
Vehicle Engineering
Research subject
X RSXC; 80 Road: Traffic safety and accidents, 85 Road: Personal injuries
Identifiers
urn:nbn:se:vti:diva-7342 (URN)
Conference
16th International Conference Road Safety on Four Continents. Beijing, China (RS4C 2013). 15-17 May 2013
Available from: 2014-10-29 Created: 2014-10-29 Last updated: 2014-11-07Bibliographically approved
Othman, S., Thomson, R. & Lannér, G. (2011). Identifying critical road geometry parameters affecting crash rate and crash type. In: : . Paper presented at Association for the Advancement of Automotive Medicine (AAAM), 53rd Annual Meeting - October 4-7, 2009 - Baltimore. Barrington: Association for the Advancement of Automotive Medicine
Open this publication in new window or tab >>Identifying critical road geometry parameters affecting crash rate and crash type
2011 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The objective of this traffic safety investigation was to find critical road parameters affecting crash rate (CR). The study was based on crash and road maintenance data from Western Sweden. More than 3000 crashes, reported from 2000 to 2005 on median-separated roads, were collected and combined with road geometric and surface data. The statistical analysis showed variations in CR when road elements changed confirming that road characteristics affect CR. The findings indicated that large radii right-turn curves were more dangerous than left curves, in particular, during lane changing manoeuvres. However sharper curves are more dangerous in both left and right curves. Moreover, motorway carriageways with no or limited shoulders have the highest CR when compared to other carriageway widths, while one lane carriageway sections on 2+1 roads were the safest. Road surface results showed that both wheel rut depth and road roughness have negative impacts on traffic safety.

Place, publisher, year, edition, pages
Barrington: Association for the Advancement of Automotive Medicine, 2011. p. 11
Keywords
Curve (road), Degree of curvature, Geometric design, Surfacing, Evenness, Rutting (wheel), Safety, Kurvor, Krökning, Vägutformning, Beläggningar, Jämnhet, Spårbildning, Säkerhet
National Category
Infrastructure Engineering
Research subject
Road: Traffic safety and accidents, Road: Geometric design and traffic safety; Road: Highway design, Road: Surfacing
Identifiers
urn:nbn:se:vti:diva-5199 (URN)
Conference
Association for the Advancement of Automotive Medicine (AAAM), 53rd Annual Meeting - October 4-7, 2009 - Baltimore
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2014-09-18Bibliographically approved
Othman, S., Thomson, R. & Lannér, G. (2011). Safety analysis of horizontal curves using real traffic data. Journal of transportation engineering, 140(4)
Open this publication in new window or tab >>Safety analysis of horizontal curves using real traffic data
2011 (English)In: Journal of transportation engineering, ISSN 0733-947X, E-ISSN 1943-5436, Vol. 140, no 4, p. 17Article in journal (Refereed) Published
Abstract [en]

Researchers are still seeking a better understanding of the parameters that affect safety in horizontal curves. Curves are one of the most critical sections of the road network contributing to a high percentage of serious runoff accidents and lane-changing crashes. Moreover, driving in curves requires combined control of both steering and speed, taking into account the dynamic response and limits of the car. The objectives of this study were to evaluate the safety performance of horizontal curves by analyzing vehicle dynamic signals, such as lateral acceleration and speed, as well as quantitative analysis of lane-changing maneuvers. The study uses real traffic environments where driver behavior and vehicle response data were recorded and stored during regular operations without subjecting the driver to any experimental controls. A total of 96 curves, equally distributed for left and right turn directions, have been collected and grouped according to their radii. The analysis identified frequent overtaking and lane-change maneuvers on the curves, of which 20% more lane changes occurred on right curves than on left curves. Lane-change maneuvers also increased significantly with increasing curve radius. The curve entrance was found to be the most dangerous segment of a curve. Current design practice assumes the safety risk is constant when driving along horizontal curves. The results also showed that drivers consider curve radius in choosing their driving speed rather than the posted speed limit of the curves. The study showed how road design influences the driver's strategy by establishing links between curve features, vehicle dynamic responses, and the driver's behavior. Analyzing road characteristics gave insight into how road geometry affects the vehicle dynamics relevant to safety and driving strategy through curves. The findings are useful inputs for reviewing curve design, selecting appropriate countermeasures, and improving active safety devices.

Place, publisher, year, edition, pages
American Society of Civil Engineers (ASCE), 2011. p. 17
Keywords
Curve (road), Degree of curvature, Acceleration, Traffic lane, Driving (veh), Behaviour, Safety, Geometric design, Kurvor, Krökning, Acceleration, Körfält, Fordonskörning, Beteende, Säkerhet, Vägutformning
National Category
Infrastructure Engineering
Research subject
80 Road: Traffic safety and accidents, 82 Road: Geometric design and traffic safety
Identifiers
urn:nbn:se:vti:diva-5202 (URN)10.1061/(ASCE)TE.1943-5436.0000626 (DOI)000332747900008 ()978-91-7385-585-3 (ISBN)
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2017-12-06Bibliographically approved
Othman, S., Thomson, R. & Lannér, G. (2011). Using naturalistic field operational test (FOT) data to identify horizontal curves. Journal of transportation engineering, 138(9), 1151-1160
Open this publication in new window or tab >>Using naturalistic field operational test (FOT) data to identify horizontal curves
2011 (English)In: Journal of transportation engineering, ISSN 0733-947X, E-ISSN 1943-5436, Vol. 138, no 9, p. 23p. 1151-1160Article in journal (Refereed) Published
Abstract [en]

Investigations to identify relationships between crashes and road features usually deal with effects of only one or two of the main components of traffic safety, i.e., human, vehicle, and infrastructure performance. There are several contributing factors of the components that together lead to a crash. This study devises an approach to include information from all three components in a system using field operational test (FOT) data. FOT data are recorded from real-life driving that is different from traffic simulations and specific on-site data collection. The study focuses on identifying horizontal curves using FOT and provides access to vehicle and human response data at the exact time when the vehicle drove in a specific location. A method has been developed to derive path radius and to identify start-end points of horizontal curves using FOT data. With this information, vehicle response signals and human behavior data can then be arranged on a common axis referenced to the curve. The approach also identifies lane changing maneuvers on curves that can be used to evaluate potential crash triggers. The application of this method allows for reviewing changes in the regulatory speed limit, curve geometry, or crash history and thus evaluates the design of curves and choosing appropriate countermeasures.

Place, publisher, year, edition, pages
Göteborg: American Society of Civil Engineers (ASCE), 2011. p. 23
Keywords
Curve (road), Degree of curvature, Driver, Behaviour, Safety, Geometric design, Kurvor, Krökning, Förare, Beteende, Säkerhet, Vägutformning
National Category
Infrastructure Engineering
Research subject
80 Road: Traffic safety and accidents, 82 Road: Geometric design and traffic safety
Identifiers
urn:nbn:se:vti:diva-5201 (URN)10.1061/(ASCE)TE.1943-5436.0000408 (DOI)000312767400008 ()978-91-7385-585-3 (ISBN)
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2017-12-06Bibliographically approved
Othman, S., Thomson, R. & Lannér, G. (2010). Are driving and overtaking on right curves more dangerous than on left curves?. Paper presented at 54th Annual Scientific Conference; Las Vegas, USA; 17-20 October 2010. Annals of advances in automotive medicine, 54, 253-264
Open this publication in new window or tab >>Are driving and overtaking on right curves more dangerous than on left curves?
2010 (English)In: Annals of advances in automotive medicine, ISSN 1943-2461, Vol. 54, p. 11p. 253-264Article in journal (Refereed) Published
Abstract [en]

It is well known that crashes on horizontal curves are a cause for concern in all countries due to the frequency and severity of crashes at curves compared to road tangents. A recent study of crashes in western Sweden reported a higher rate of crashes in right curves than left curves. To further understand this result, this paper reports the results of novel analyses of the responses of vehicles and drivers during negotiating and overtaking maneuvers on curves for right hand traffic. The overall objectives of the study were to find road parameters for curves that affect vehicle dynamic responses, to analyze these responses during overtaking maneuvers on curves, and to link the results with driver behavior for different curve directions. The studied road features were speed, super-elevation, radius and friction including their interactions, while the analyzed vehicle dynamic factors were lateral acceleration and yaw angular velocity. A simulation program, PC-Crash, has been used to simulate road parameters and vehicle response interaction in curves. Overtaking maneuvers have been simulated for all road feature combinations in a total of 108 runs. Analysis of variances (ANOVA) was performed, using two sided randomized block design, to find differences in vehicle responses for the curve parameters. To study driver response, a field test using an instrumented vehicle and 32 participants was reviewed as it contained longitudinal speed and acceleration data for analysis. The simulation results showed that road features affect overtaking performance in right and left curves differently. Overtaking on right curves was sensitive to radius and the interaction of radius with road condition; while overtaking on left curves was more sensitive to super-elevation. Comparisons of lateral acceleration and yaw angular velocity during these maneuvers showed different vehicle response configurations depending on curve direction and maneuver path. The field test experiments also showed that drivers behave differently depending on the curve direction where both speed and acceleration were higher on right than left curves. The implication of this study is that curve direction should be taken into consideration to a greater extent when designing and redesigning curves. It appears that the driver and the vehicle are influenced by different infrastructure factors depending on the curve direction. In addition, the results suggest that the vehicle dynamics response alone cannot explain the higher crash risk in right curves. Further studies of the links between driver, vehicle, and highway characteristics are needed, such as naturalistic driving studies, to identify the key safety indicators for highway safety.

Place, publisher, year, edition, pages
Association for the Advancement of Automotive Medicine, 2010. p. 11
Keywords
Curve (road), Degree of curvature, Right, Left, Accident, Risk, Overtaking, Vehicle stability, Safety, Geometric design, Simulation, Kurvor, Krökning, Höger, Vänster, Olyckor, Risk, Omkörning, Fordonsstabilitet, Säkerhet, Vägutformning, Simulering
National Category
Infrastructure Engineering
Research subject
80 Road: Traffic safety and accidents, 82 Road: Geometric design and traffic safety
Identifiers
urn:nbn:se:vti:diva-5200 (URN)21050608 (PubMedID)2-s2.0-84979846119 (Scopus ID)
Conference
54th Annual Scientific Conference; Las Vegas, USA; 17-20 October 2010
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2016-08-10Bibliographically approved
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