A New Metric for the Assessment of Driver Crash Risks

Lead Research Organisation: University of Essex
Department Name: Psychology

Abstract

Road accidents account for thousands of deaths and injuries each year in Great Britain. Central to concerns for road safety are younger and older drivers who are reported to have crash rates per mile driven or per trip made that are much greater than drivers of other ages. Policymakers in Great Britain and around the world have responded to the high crash rates of these two groups of drivers by proposing initiatives to reduce their exposure to risk. Graduated licensing systems in the United States and other countries impose restrictions on young drivers (e.g., carrying passengers, curfews). The Department for Transport has recommended similar graduated licensing in Great Britain. At present, license renewal regulations are imposed on older drivers to identify visual, cognitive, and physical impairment among older adults that might put them at increased risk as drivers.

This research project will investigate a bias in driver crash risks that potentially exaggerates the risks of young and elderly drivers, leading to inaccurate reports of driver crash risks as well as misinforming road safety policies designed to safeguard road users. We will develop a new metric for the assessment of driver crash risk that overcomes previous bias with a view to better informing road safety policies and the general public. Public misconceptions about driver crash risks impact on people's lives such as by discouraging older drivers from renewing their driver license, which directly affects their mobility, health, and well-being.

Shared beliefs and misconceptions about the risks of young and elderly drivers have the potential to influence eye-witness accounts and police officers' reporting of road accidents, especially with regard to the allocation of driver blame. Age bias in police reporting has direct implications for the reliability of police reported accident data on which estimates of crash risk are based. This project investigates the potential for police reporting bias with a series of psychological studies that identify situations where reporting bias is most likely to occur, enabling recommendations to be made for how such bias can be reduced in road accident assessment.

Planned Impact

Policymakers are charged with the difficult role of designing policies to safeguard the public. With regards to road safety, these policies must balance the benefits of driving with a need for public safety. For example, license renewal regulation is effective for older drivers who are impaired and may safeguard them from potential injury. However, an unintended outcome of license renewal regulation has been to discourage older drivers from renewing their driving license, which compromises their mobility with negative consequences for their health and well-being. It is extremely important then that such policies are informed by accurate assessments of driver risk. The outputs of this research will impact on policymakers by providing reliable and accurate assessments of driver risk, which will enable them to allocate resources appropriately to safeguard road users.

For all police reported crashes in Great Britain the investigating officer records factors that they believe may have contributed. These factors include driver error (e.g., failure to look properly) and impairment (e.g., alcohol consumption) among others. The reporting officer may also draw on reports of witnesses in the general public. Accident reports are subjective judgments and are susceptible to bias. By identifying situations in which bias is most likely to occur, this project will inform police officers about how they can reduce the risk of bias in their reporting of road accidents. In turn, this will improve the accuracy and reliability of driver risk estimates that are based on police reported data.

Vehicle insurers rely on estimates of potential loss when identifying the appropriate insurance cost for a driver. Driver age is central to these assessments and young drivers in particular are charged a high premium for vehicle insurance. Insurers often rely on their own risk assessments. This project will identify bias in previous estimates of driver crash risk that will have influenced insurers own risk assessments. The outputs of this research will impact on vehicle insurers by providing a more accurate tool for assessing driver crash risk. The project also investigates potential bias in police and witness reports of road accidents. Vehicle insurers rely on the accuracy of these reports in their evaluation of insurance claims. This project will inform insurers about the situations in which bias is most likely to occur.

Investigating bias in crash rate estimation and police practice in reporting of road accidents, this project will impact on road safety policymaking, vehicle insurer practice, and the society in general through improvements in public health and well-being.

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/M017877/1 01/05/2015 31/12/2015 £198,635
EP/M017877/2 Transfer EP/M017877/1 05/01/2016 15/08/2017 £166,474
 
Description New statistical methods were developed for the assessment of driver safety. The studies revealed important new insights into the safety of young and older drivers. While still at risk, young drivers were found to be less of a danger on the road than implied by traditional assessments of their crash risk. Also in contrast with previous reports, our new analytic methods revealed that older adults show no considerable increase in their crash risk compared to middle-age drivers. The research also revealed new insights into the causes of road accidents by combining analyses of accident records with the expert views of experienced police officers and lay views of the driving public. It was revealed that police officers and the public have accurate views of the typical causes of road accidents. However, the views of police officers revealed inadequacies in the current road accident reporting methods, which can be used to inform future changes to UK accident reporting procedures. For example, police officers perceive distraction by mobile phone use, and use of drugs and alcohol by drivers as much more frequent causes of road accidents than implied by existing accident records. These latter findings indicate that some factors contributing to road accidents may be greatly under-reported in road accident records, potentially delaying the provision of much needed resources.
Exploitation Route The findings of the research have been used to inform the development of a new mobile road accident reporting device by the UK Department for Transport (DfT) that will be used across the UK to report on road accidents at the roadside, replacing current procedures. The findings are also being used by the UK DfT to review the current methods for identifying the causes of road accidents.
Sectors Government, Democracy and Justice,Transport

 
Description During the period of the award and following the project, Dr Rolison has been communicating the findings and other outputs of the grant to the Department for Transport (DfT). The DfT is currently reviewing the current UK road traffic accident reporting practices (known as "STATS19"). The findings of the grant have revealed that police officers' views on the causes of road accidents are at odds with the recorded road accident data. Dr Rolison was invited to present the grant findings to an expert panel organized by the DfT to review the current accident reporting practices. Dr Rolison also contributed to panel discussions. Consequently, the DfT are incorporating the findings of the grant to inform a new set of road accident reporting practices to be used in the UK. The research outputs and impact engagement (e.g., impact events documented in Researchfish) have also resulted in the UK DfT acquiring a contract to develop a mobile accident reporting device/app for recording details of road accidents at the roadside. One of the motivations for this development is that the funded project revealed that memory bias can result from delayed reporting of road accidents by police officials. The mobile device is in later stages of development and will initially be used by selected police stations and units before being used across the UK. The device reduces police officer workload, increasing public sector efficiency, by reducing duplication in accident reporting. The device also has the potential to improve survival, morbidity, and quality of life of road users by improving insight into road accident causation through improvement in the reliability of accident data.
Sector Government, Democracy and Justice,Transport
Impact Types Policy & public services

 
Description Development of a mobile road accident reporting device
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
Impact The research outputs and impact engagement (e.g., impact events documented in Researchfish) resulted in the UK Department for Transport acquiring a contract to develop a mobile accident reporting device/app for recording details of road accidents at the roadside. One of the motivations for this development is that the funded project revealed that memory bias can result from delayed reporting of road accidents by police officials. The mobile device is in later stages of development and will initially be used by selected police stations and units before being used across the UK. The device reduces police officer workload, increasing public sector efficiency, by reducing duplication in accident reporting. The device also has the potential to improve survival, morbidity, and quality of life of road users by improving insight into road accident causation through improvement in the reliability of accident data.
 
Description Transport-Technology, Research and Innovations Grant
Amount £15,024 (GBP)
Organisation Department of Transport 
Sector Public
Country United Kingdom
Start 01/2016 
End 03/2016
 
Title Crash risk metric 
Description Traditional methods for assessing driver crash risk have relied on drivers' annual mileage to adjust for their exposure to risk. However, this approach may underestimate the risk exposure of older drivers because older drivers tend to avoid highways and travel more on urban and inner-city roads that present greater hazards. The funded project developed "risk exposure density" as a new index of exposure that incorporates driver mileage, frequency of travel, and travel duration. The funded research showed that mileage-based assessments of crash risk can produce misleading accounts of driver risk. The new metric, risk exposure density, incorporates multiple components of travel and was shown to reduce bias caused by any single indicator of risk exposure. The metric is available in a published research article produced by the project and is publicly available for use by researchers and practitioners. 
Type Of Material Model of mechanisms or symptoms - human 
Year Produced 2017 
Provided To Others? Yes  
Impact The metric tool developed by the project is publicly available for use by others, including researchers and practitioners. The publication is recent and future impact is expected. 
URL http://repository.essex.ac.uk/19888/
 
Description Partnership with UK Department for Transport (DfT) 
Organisation Department of Transport
Country United Kingdom 
Sector Public 
PI Contribution Dr Rolison was invited to present findings of the awarded project to the Standing Committee on Road Accident Statistics (SCRAS) at the UK Department for Transport (DfT). The committee oversees the procedures for road accident data collection. The research findings of the project were included in the committee's review of the current UK road accident reporting procedures. Following his initial involvement, Dr Rolison was invited to become a member of committee to make future contributions to the committee.
Collaborator Contribution The UK Department for Transport (DfT) enabled Dr Rolison to join a network of individual working within road safety, which opened up new opportunities for collaboration.
Impact The collaboration is multi-disciplinary as it involves partners from outside academia, including government and police officials. The collaboration has resulted in a funded project within the UK DfT for developing a mobile road accident reporting device inspired by research outcomes of the funded project.
Start Year 2016
 
Description Contribution to the STATS19 review committee 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Since beginning the awarded project, Dr Jonathan Rolison has been engaging closely with the UK Department for Transport (DfT). Dr Rolison has met with members of the DfT on a number of occasions to communicate regular outputs of the grant. Dr Rolison was invited to join the expert panel for reviewing the STATS19 reporting practices, which is the current method used in the UK for reporting road traffic accidents. Dr Rolison presented the grant findings to the panel in an invited talk and formed part of the panel discussion regarding policy changes to the current accident reporting procedures.
Year(s) Of Engagement Activity 2016
 
Description Cursed by their small numbers: Debunking the myth that young and elderly drivers have high crash risks 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Rolison gave a research talk at the 2016 American Public Health Association conference in Denver, Colorado, US. The talk was attended by researchers in the field. The talk opened the findings of the grant to an international audience.
Year(s) Of Engagement Activity 2016