Evaluation of ITS applications on the Køge Bugt Motorway, Denmark

1. Evaluation of ITS applications on the Køge Bugt Motorway, Denmark Jens Toft Wendelboe Technical Consultant Traffic Management Department Danish Road Directorate

2. Contents of presentation • Background • ITS applications used on the Køge Bugt Motorway • Evaluation – aspects regarding traffic and technical performance

3. Køge Bugt Motorway: 2002 - 2003 Widening of the Køge Bugt Motorway

4. Issues and applications Issues leading to implementation of ITS • Safety • Traffic flow Selected ITS applications • Dynamic speed limits • Dynamic route guidance • Traffic monitoring

5. Dynamic speed limits and traffic monitoring

6. Display near Greve Dynamic route guidance

7. Evaluation purposes • To investigate drivers reactions and satisfaction • To examine technical performance • To gain experience with ITS applications to be used in future projects

8. Surveys Dynamic speed limits • Do drivers comply with displayed speed limits? • Does the system provide more uniform speeds? • Does the system provide a more uniform flow? • Do the displays change as specified? Dynamic route guidance • Will drivers change to the least congested route? • What are the travel time reductions? • Are displayed delays in accordance with experienced delays? Both • What do the drivers think of the applications?

9. Data & method Analyses are based on • Loop detector data • System data/log files • Data obtained via questionnaire among drivers • Experiences from daily service (TIC) Types of analyses • Before and after studies (only after studies when examining technical performance and drivers´ opinion)

10. Results – dynamic speed limits • Drivers to not comply with displayed speed limits unless traffic conditions force them to • However, speeds are decreased by approximately 5 km/h overall • The faster people drive, the greater the speed reduction • Speeds have only become more uniform at places and times with heavy congestion • The same tendency applies when it comes to traffic flow • Important: drivers receive information about congestion ahead, and they respond to the warning: this could mean reduced risk of rear-end collisions

11. Problems with errors in both directions in extreme situations (accidents) • There have been problems with errors in displayed speed limits towards Copenhagen • Only few errors in displayed speed limits towards Køge

12. Results – dynamic route guidance • Drivers do not change route unless there is a considerable difference in the displayed delays – special days • Up to 14% of the traffic has been redistributed in cases of major differences in displayed delays • Displayed delays often varies significantly from experienced delays • Drivers find it difficult to understand the displayed information • Due to unforeseen variations, there have been no travel time reductions in general

13. Questionnaire – main results 2.500 postcards were distributed and the return rate was app. 25% • App. every second driver feels safer with dynamic speed limits • App. every second driver is indifferent • App. 4% feels less safe Drivers are having trouble understanding displayed delays, due to: • Lack of knowledge regarding route numbers • Displayed information is too complicated • Too much information on the displays • Display/letters are too small

14. 68% of the drivers: the difference in displayed delays has to be 5 minutes or more, otherwise they will stay on the route first chosen Comments reveal that a lot of drivers think that the displayed information/speed limits rarely correspond with actual conditions Never the less, more than 80% of the drivers were favourably disposed to the ITS applications

15. Overall assessment Conditional success: • Applications function, but not always • Applications affect drivers, but not sufficiently • Applications are likely to produce better results if technical performance is improved

16. Thank you for your attention! Any questions?