1. Short term forecast model
Travel times on M3
6 October 2005
VIKING

2. Short term forecast model
Travel Time Information System M3
Detectors
for speed
measurements
Service Level
(website)
Actual Travel Time
(website/VMS)
On-line
Database
Forecasted
Travel Time
(website)
Historical
Database
Best/worst
travel time
6 October 2005
VIKING

3. Short term forecast model
6 October 2005
VIKING

4. Short term forecast model
6 October 2005
VIKING

5. Short term forecast model
6 October 2005
VIKING

6. Short term forecast model
6 October 2005
VIKING

7. Short term forecast model
6 October 2005
VIKING

8. Short term forecast model
6 October 2005
VIKING

9. Short term forecast model
6 October 2005
VIKING

10. Monday morning segment 3
Travel
Time
Min.
6 October 2005
VIKING

11. Average travel times - north morning – segment 3
Minutes
6 October 2005
VIKING

12. Short term forecast model
Clean-up in data:
Segments and periods with incidents
excluded from database.
Incidents eg.
Lost load
Stopped vehicle
Accident
Over 3 months:
50 incidents logged
1,3 % of peak-hour period segment-minutes excluded
Furthermore exclude:
Holidays, saturdays/sundays
Segments without measurements
6 October 2005
VIKING

13. Short term forecast model
Model type:
Model 1: 15 min’s forecast based on difference from average
- measurements 0, 1, 2 and 10 minutes back
Travel time t+15 = average travel timet+15 +
a0(travel timet - average travel timet)+
a1(travel timet-1 - average travel timet-1)+
…..
a10(travel timet-10 - average travel timet-10)+
epsilont+15
6 October 2005
VIKING

14. Short term forecast model
Model types:
Model 1: 15 min’s forecast based on difference from average
- measurements 0,1, 2 and 10 minutes back
Model 2: as 1, but 30 min’s forecast
model both for morning peak and evening peak
on 6 road segments
northbound and southbound
total 2x6x2 = 24 models of each type
6 October 2005
VIKING

15. Statistical variation on travel time
Model evaluation by:
Statistical variation on travel time
% large errors in travel time forecast
6 October 2005
VIKING

16. 6 October 2005
VIKING

17. 6 October 2005
VIKING

18. 6 October 2005
VIKING

19. Short term forecast model
6 October 2005
VIKING

20. 6 October 2005
VIKING

21. Monday morning segment 3
Travel
Time
Min.
6 October 2005
VIKING

22. Monday evening segment 3
Travel
Time
Min.
6 October 2005
VIKING

23. Short term forecast model
Implementation:
On-line from end of the year
recalibration of coefficients as travel pattern changes
Further development:
smaller segments
correllation between segments
adaptive system (coefficients change over time)
travel time forecasts at accidents/ unnormal situations
6 October 2005
VIKING

24. Short term forecast model
Best practice cases identified:
15 min’s forecasts on traveltime possible on motorways
Specific aspects:
time series models applicable
different models for each day of the week
traffic pattern different for each segment of the motorway
Regional or global ?
model developed locally,
probably globally applicable for commuter traffic
6 October 2005
VIKING

25. Thank you for listening
6 October 2005
VIKING