Mapotempo Web evolves
A new and more accurate route computation method for Mapotempo Web
Mapotempo solutions are based on free components. For instance, for Mapotempo Web and the Routing API we use the open source routing machine OSRM.
Works diffusion : consider the urban density to determine the speed on a segment of the road network
OSRM routing machine use OpenStreetMap’s data. Our development team recently diffuse its works from the use of OSRM. The aim of theses developments was to consider the urban density to determine the travel speed on a segment of the road network. When this speed is determined, the routing machine is able to calculate the travel time on each segment of the road network. Following this the routing machine can select the fastest route for a given path.
You can find the source code of our works here : github.com/Mapotempo
Why did we do these works ?
To compute the speed on a road segment, OSRM only considers the road type : highway, trunk road, primary road, street etc. However we observed that the real speed does not only depends on the road type, it also depends on the urban context. Indeed, speed on a primary road in a city or in the countryside will not be the same. Moreover, this primary road can cross several urban contexts. So, to refine the speed computation on a segment of the road network it is more accurate to consider : road type AND urban density. Refine this speed for each segment of the road finally provides a more accurate result to identify the fastest route between two points.
What is the new calculation method to get the wished result ?
Click on picture to enlarge
The travel time for each segment was determined by the travel speed. The travel speed was determined by the road type (highway, primary road, secondary road, street etc.).
Click on picture to enlarge
The travel time for each segment was determined by the travel speed. The travel speed is determined by the road type AND by the urban density of each road portion (urban dense, urban, inter-urban).
This calculation method provides a more accurate result for determining the travel time of each segment of the road network. When the fastest route is selected, the result is more accurate and is also closer to reality.
Used data
To get the expected results, it was necessary to define the different levels of urban density. To do this, we have used the European database Corine Land Cover. This project, leaded by the European Environment Agency, provides soil biophysical occupancy data and covers 39 states.
Example of 3 levels of urban density for Nice. Data from Corine Land Cover
In the future we could extend the consideration of urban density to other countries by using, in particular, Canadian database GeoBase Land Cover or the US Land Cover for United States.
Works that bring a new route computation method for Mapotempo Web
Our Europeans users can now use the new route computation method (“light vehicle”) on three levels: dense urban, urban and inter-urban. It automatically adjusts the travel speed according to the urban density on these three levels. For example, if your route has destinations in dense urban areas, others in urban areas and others in inter-urban areas, the route computation automatically considers these parameters to apply the correct speed to each level of the route (urban dense, urban and inter-urban).
