Sustainable Route Navigation : is there harmony between route planners and policy principles for sustainable mobility? In-Vehicle route planning is used to support a driver’s route choice and to guide a driver to his/her destination. Web route planners and navigation systems calculate these routes. However, the suggested route takes less account of environmental aspects, which could lead to cut-through traffic. Nonetheless, route-guiding systems may provide opportunities to stimulate a sustainable usage of the road network wherefore an integration of route planning and measures to improve traffic liveability and safety is essential. Policy principles may provide a first step towards a more sustainable route planning. The Flanders Spatial Structure (RSV) plan describes certain categories of roads for the optimisation of the road network based on selectively prioritising either accessibility or live-ability. Additionally, these categorizations are the basic principles of the Flemish signposting along regional roads and highways. This report describes the basic ideas of route planners (web-based or navigation system) and the policy principles involved in route planning. The policy-made road categorization and route choices deviate from the popular route navigation systems. This issue is indicated by three case studies, by examining to what extent route planners apply the principles of this (policy-made) road categorization while calculating a proposed route. Results of the research show that different route planners may suggest different routes. These routes can also differ from the desired route based on the Flanders Spatial Structure plan or the Flemish signposting. By comparing both planned static and time-dependent routes with the corresponding desired routes, differences in road usage are apparent. These deviations are mostly found in the use of low and/or high-categorized roads. Route planners to guide through-traffic without considering the lower function of these roads frequently use especially roads of the lowest category -which should only be used to give access to adjacent parcels. For some of these suggested routes, the desired route is a feasible alternative. Based on this research, a workshop was organised to involve all relevant stakeholders. These were policy representatives, administrations, research facilities and private companies. Five discourses concerning this subject are revealed and described. It is concluded that the implementation of the Flemish road categorization in routing algorithms has the potential to stimulate more sustainable driving behavior with more sustainable route choices. In this context, route planners should be viewed as an opportunity to enhance sustainable routing. (Author/publisher)
Samenvatting