The payback period for a drowsy driver warning system was estimated at 0.8 to 10 years for heavy vehicles.

Cost benefit analysis of drowsy driver warning system developed in Sweden.

November 27, 2008

Summary Information

This cost benefit analysis was conducted as part of the DROWSI (Drowsiness Intervention) project. DROWSI was a national research project conducted by Sweden's Intelligent Vehicle Safety Systems program. The DROWSI project was a collaborative initiative between AB Volvo, Volvo Cars, Autoliv, the Stress Research Institute at Stockholm University, VTI, Chalmers University of Technology and the Swedish Road Administration.

Driver sleepiness is considered to be a major cause and contributor to traffic crashes. Research suggests that 10 to 20 percent of all crashes are caused by driver sleepiness. A warning system addressed to sleepy drivers could be a countermeasure to reduce the number of sleep related crashes. A cost benefit analysis was performed to relate the possible traffic safety benefits from the installation of a sleepiness warning system to the costs.

Payback periods for a drowsy driver warning system were estimated based upon initial expected crash cost, reductions due to the warning system, and the installation costs as follows:
  • Passenger cars, 5 to 75 years before installation costs recovered.
  • Trucks, 3 to 36 years before installation costs recovered.
  • Heaviest trucks (load capacity 16,000 to 17,000 kg), 0.8 to 10 years before installation costs recovered.
There are major uncertainties when it comes to the potential of such a system, considering the size of the sleepiness problem and to what degree drivers will change their behavior and thereby avoid crashes when a system is installed. The numbers given in this report should be seen as approximations and depend heavily on the assumptions made.

Benefit Comments

No comments posted to date

Comment on this Benefit

To comment on this summary, fill in the information below and click on submit. An asterisk (*) indicates a required field. Your name and email address, if provided, will not be posted, but are to contact you, if needed to clarify your comments.


DROWSI Project Cost Benefit Analysis

Author: Lina Jonsson

Published By: Swedish National Road and Transport Research Institute

Source Date: November 27, 2008



Average User Rating

0 ( ratings)

Rate this Benefit

(click stars to rate)

Goal Areas


Typical Deployment Locations



None defined

Benefit ID: 2011-00716