A European Model Estimated That Mandatory Deployment of Vulnerable Road User Detection and Warning Systems on Buses And Coaches Can Have A Benefit-To-Cost Ratio of 10.2 Over Two Years (2026-2027).

European Study Assessed Potential Safety Benefits of Advanced Driver Assistance Systems (ADAS) Factory-Fitted or Planned to be Retrofitted in Near Future Across the European Union Fleet.

Date Posted

Study on the Feasibility, Costs and Benefits of Retrofitting Advanced Driver Assistance to Improve Road Safety

Summary Information

Advanced Driver Assistance Systems (ADAS) are vehicle-based intelligent safety systems, developed and deployed by vehicle manufacturers, which have the potential to improve road safety in terms of crash avoidance, crash severity reduction, and protection. This study examined the technical feasibility of various retrofit ADAS, and specifically evaluated Forward Collision Warning (FCW), Lane Departure Warning (LDW), Advanced Driver Distraction Warning (DDR-ADR), Speed Limit Information (SLI), Reversing Detection (REV), Tire Pressure Monitoring (TPM) system, Vulnerable Road User Detection and Warning on front and side of vehicle (VIS-DET), Turn Assistant for trucks, and 112 eCall. Some of the ADAS considered in this study have been available and factory-fitted in vehicles since 2015 and 2018, and some are planned to be implemented in 2022 and 2024. The current penetration rates of ADAS in the European Union (EU) vehicle fleet and their expected development over time were assessed, and various policy measures and their expected effects were developed. The expected impacts of retrofitting ADAS under two different policy options were tested in a cost-benefit analysis (CBA).


The estimation of the selected retrofit ADAS’ safety potential was conducted by assessing the proportion of accidents considered preventable with the help of the retrofitted systems. The safety impact assessment was based on the descriptions of ADAS and their functionalities provided by the vehicle manufacturers. Based on these, the share and type of vehicles where the ADAS can be retrofitted were identified. The safety effects were calculated based on the estimates of the safety effects reported in earlier studies. The first estimates of safety effects considered 100 percent penetration rate and 100 percent usage of ADAS. Current (2019) penetration rates for factory-fitted ADAS vary in the 1-72 percent range depending on the technology and the vehicle type. As for the retrofit ADAS, the current penetration rates are quite low lingering around 0.2-0.4 percent considering all the vehicle fleets in the EU. In the CBA, the effects were analyzed over a period of 15 years, starting in 2026, when the first policy measures are put into place (e.g., an awareness raising campaign and a subsidy scheme for implemented policies) and runs until 2041. 

Two different sets of policy measures were assessed: Policy Option 1 (PO1) included both a financial incentive and an awareness campaign (voluntary measures). Policy Option 2 (PO2) assumed a mandatory deployment of retrofit ADAS for all vehicles during a period of 2 years (2026–2027). The costs included in the CBA were: purchase and installation costs, subsidy costs, campaign costs and inspection costs. Damage, maintenance, standardization and certification costs were assumed to be negligible and hence not taken into account in the CBA. The benefits of retrofitting ADAS were a monetization of prevented casualties as a result of retrofit ADAS. Among the vehicle types considered in this study were passenger cars, buses and trucks. 



  • The number of prevented casualties (as a result of retrofitting) over the period 2026–2041 as a percentage reduction relative to the baseline assessment was estimated to be 5.2 percent for the FCW, LDW, and SLI bundle for PO2. Benefit-to-Cost Ratio (BCR) for the FCW, LDW, and SLI bundle was estimated as high as 1.6 for PO1, depending on the vehicle types in the fleet.
  • BCR for DDR was estimated as high as 4.7 for PO2, depending on the vehicle types in the fleet.
  • BCR for TPM was estimated as high as 1.4 for PO2, depending on the vehicle types in the fleet.
  • VIS-DET was estimated to offer a positive BCR (as high as 7.3 for PO1 and 10.2 for PO2) for both policy options for buses and coaches, proving to be highly cost effective for these two vehicle types. Similarly, the BCR for buses and coaches for SLI (up to 5.6) were positive for both policy options.