Modified vehicles

Modifying a passenger vehicle may impact the safety of the occupants of the modified vehicle as well as create hazards for occupants other vehicles and pedestrians. Common after-market modifications made to vehicles include raising or lowering the frame, installing tinted headlights or fog lights, or tinting windows. When a vehicle is raised, braking performance and stopping distances can be significantly affected. The section of the vehicle that comes in contact with the pedestrian is rigid compared to the hood of a vehicle, resulting in more severe injury to the struck pedestrian.

Although information on the percentage of pedestrian-vehicle crashes involving modified vehicles is not available due to the limitations of police collision data reporting, most jurisdiction recognize that certain types of vehicle modifications can affect the safety of its operation. Consequently, jurisdictions specify the types of after-market vehicle modifications that are allowed. Depending on the vehicle modification carried out, certificates of vehicle fitness may be required before vehicles are allowed on the road.

As an example, the provinces of Manitoba and Saskatchewan provide a list of vehicle modifications that can be made and after-market accessories that can be fitted on a vehicle. The list includes basic guidelines on certain vehicle modifications and clearly specifies that the modifications or after-market accessories must meet specific requirements (e.g. bumper height and horizontal centre and vehicle ride height) (Manitoba Public Insurance, 2015, Regina Police Service, 2011).

In New Zealand, vehicle modifications may require a low volume vehicle (LVV) certificate, at a cost of between $250 and $800, in order to obtain a warrant of fitness. A vehicle modification that frequently requires LVV certification is a modified suspension, which could alter vehicle handling (New Zealand Transport Agency, 2015, New Zealand Automobile Association, 2015). In the state of Western Australia, modified vehicles must comply with Australian design rules and Australian vehicle standard rules and regulations (RAC, 2015).

Research carried out by Desapriya et al. (2010) indirectly identified the safety issue related to crashes involving pedestrians and vehicles with an increased vehicle frame height. The authors carried out a systematic review and meta-analysis to quantify and compare the impact of light truck vehicles (LTVs) versus conventional cars on pedestrian fatal injury. The results of the 11 studies reviewed showed that pedestrians’ risk of sustaining a fatal injury is 50% greater in collisions with LTVs than in collisions with conventional passenger cars. Roudsari et al. (2004) also carried out research that compared the injury and mortality rates of pedestrians involved in crashes with LTVs and passenger vehicles. Their results showed that after adjusting for pedestrian age and impact speed, the risk of death for pedestrians involved in crashes with LTVs was 3.4 times higher than that for passenger vehicles.

A study by Keall et al. (2014) that took a retrospective and futuristic examination of changes in fatal and serious injury rates among pedestrians associated with gradual changes in the New Zealand and Australian light passenger vehicle fleet found that both Australia and New Zealand had benefited from reduced pedestrian road trauma through improvement in pedestrian aggressivity of the vehicle fleet.

A recent study by the Insurance Institute for Highway Safety (2013) cited the increased emphasis of automotive research on making vehicle improvements that could benefits pedestrians by designing vehicle fronts that are softer if they contact pedestrians. National vehicle regulatory agencies in Canada and the United States (Transport Canada and the National Highway Traffic Safety Administration) have been considering a global technical regulation that would require tests to address pedestrian head-to-hood impacts for adults and children. The regulation known as GTR 9 is part of a United Nations' effort to harmonize certain vehicle safety standards worldwide. GTR 9 would require head impact tests for vehicle hoods but not the windshield and windshield pillar tests European regulators mandate. GTR 9 also addresses pedestrian leg-to-bumper impacts (Insurance Institute for Highway Safety, 2013).

Evidence

• Manitoba Public Insurance (2015). Registration, Vehicle Modifications. Retrieved from http://www.mpi.mb.ca/en/Reg-and-Ins/Registration/VSI/Pages/modifications.aspx
• Regina Police Service (2011). Vehicle Modifications. Retrieved from http://reginapolice.ca/vehicle/vehicle_modifications.pdf?1f814b
• New Zealand Transport Agency (2015). Modifying your vehicle. Retrieved from http://www.nzta.govt.nz/vehicle/warrants-certifications/modifying.html
• The New Zealand Automobile Association (2015). Vehicle Modification Rules and Regulations. Retrieved from http://www.aa.co.nz/cars/licensing-safety-fees/warrant-of-fitness-wof/vehicle-modification-rules-and-regulations/
• Royal Automobile Club (2014). Modifying a car. Retrieved from http://rac.com.au/motoring/motoring-advice/about-my-car/modifying-a-car?_afr.ts=1423944457338
• Desapriya, E., Subzwari, S., Sasges, D., Basic, A., Alidina, A., Turcotte, K., & Pike, I. (2010). Do light truck vehicles (LTV) impose greater risk of pedestrian injury than passenger cars? A meta-analysis and systematic review. Traffic Injury Prevention 2010; 11(1):48-56. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/20146143
• Roudsari, B., Mock, C., Kaufman, R., Grossman, D., Henary, B., & Crandall, J. (2004). Pedestrian crashes: higher injury severity and mortality rate for light truck vehicles compared with passenger vehicles. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1730093/
• Keall, M., D’Elia, A., Newstead, S., & Watson, L. (2014). Retrospective and Projected Future Impact of Characteristics of the New Zealand and Australian Vehicle
• Fleet on Pedestrian Injury, (Report No. 320), Monash University Accident Research Centre. Retrieved from http://www.monash.edu.au/miri/research/reports/muarc320.pdf
• Insurance Institute for Highway Safety (2013). Status Report, Softer vehicle fronts and pedestrian detection systems could reduce pedestrian deaths. Volume 48, No. 10, December 30, 2013. Retrieved from http://www.iihs.org/iihs/sr/statusreport/article/48/10/3