After a lot of ITS deployments it it important to evaluate the impact on traffic of these deployed ITS services. To obtain this information it has been initiated a project dealing with the calculation of vehicle lost hours.
The project objective was to obtain vehicle lost hours for both:
• Real time in main road network and corridor (namely the Arc Atlantique corridor)
• Historic vehicle lost hours in most of the road network management by Basque Goverment
The purpose is also double:
• To have a better knowledge of the traffic situation
• To measure how traffic management are impacting traffic congestions
Vehicle lost hours are obtained from aggregation of:
• Vehicle speeds
• Traffic intensity In order to have information on the first parameter (vehicles speeds) have been contracted information provided by TomTom in the road network operated by Basque Government.
This means that:
• real time vehicle speeds around 300 kms of the main corridors are provided and
• historing vehicle speeds for more than 3.000 kms of whole road network
Loops detectors and other ITS road infrastructure equipments are used for obtaining traffic intensity (number of vehicles per hour). The aggregation of this parameter together the information on vehicles speed allows to have information on vehicle lost hours and then a very useful parameter to know the traffic congestions in the roads and how well traffic management measures are used.
The above picture is one example of information obtained. The horizontal axis is the distance from French border (in the left) and the end of a main road management by Basque Goverment (at the right of the picture). The total length of this corridor is 153 kms.
The direction of the traffic is from French border to South (from left to right in the picture).
The vertical axis shows the time evolution every 30 minutes from up to down in the picture. In any case this is an agregation of the results as the vehicle speed are provided every 2 minutes.
Colors are from draft red wich means vehicle stopped until green whcih means not congestion at all.
The initial data collection started (in this case) at 4:00 am on 2nd August 2014 (Saturday) and it is possible to have the following conclussions:
• Traffic problems (congestions) already started at 4:00 am in the French border heading South (to Spain, Portugal or North of Africa).
• The main congestion point (in red color) is placed in the border between countries and they are related to the tolling areas.
• There are other congestion areas related mainly to toll areas and junctions between main motorways or corridors where road is changing from more to less number of lanes per direction.
• The information on vehicle speeds provided by probe vehicle data is not enough and it needs to be merged with information coming from infrastructure traffic intensity dectectors.
After 10 hours of congestions (red color) in the left side of the picture (French-Spanish border) the congestions is disappearing due to reduction of amount of vehicles heading South.
Just for this day (2nd August 2014) a total of 13.700 vehicle lost hours was obtained. This means an average of 20 minutes per vehicle.
The results of the tools shown there is room for coordinated French-Spanish traffic management measures.