The effect of periodic vehicle inspection on road traffic crash risk

Abstract

In the European Union (EU), periodic inspection of motor vehicles is mandatory. In Denmark, cars and vans are inspected for the first time four years after the first registration and subsequently every two years, while lorries and buses are inspected annually. Denmark follows the EU minimum requirements, but there have been considerations to increase the frequency of inspections. However, based on previous research, the positive effects on crash risk are questionable. The aim of this study was to investigate the association between time since the most recent inspection and crash risk using nationwide Danish registry data. The hypothesis is that crash risk increases proportional with time since latest inspection. Methodologically, we used a case-control design. In total, 72 089 cars, 11 289 vans, 3 101 lorries and 1 575 buses involved in crashes were included as cases. Five controls were randomly selected per case and matched by age, brand and total weight. The analyses were controlled for odometer reading and the number of brake defects at the latest inspection. The study found no association between periodic inspections and crash risk in separate analyses of each vehicle type. There were no specific effects of inspections of older vehicles aged 10 years or more. This study does not provide evidence for expanding the current Danish inspection programme with more frequent checks of vehicles. The study also indicates that vehicles that are subject to the inspection programme are in good condition such that defects have a small (not negligible) impact on crash risk.

Keywords

• buses
• cars
• crash risk
• lorries
• periodic inspection
• road traffic safety