More Attributes for each Route Link
More link attributes, like speed limit or slope, can be retrieved directly in the response. This is an alternative to calling PDE along the route, for select use cases. Use request parameter
&attributes=... list of PDE layers and attributes out of each layer ...
When to retrieve attributes directly in the route match call and when to fetch them afterwards from PDE?
In general, a matched route spans a few PDE tiles only, because the major part of a route is on functional class 1 roads (motorways) that are stored in PDE layers with large tiles. Hence, after a route match, the distinct set of tiles to load from PDE should rarely exceed 20 or 30, resulting in a few PDE requests, because each PDE request can ask for multiple tiles of multiple layers. The advantage of using PDE is that the retrieved full tile content can be cached for up to a month, and hence repeated transmission is avoided, if the assets are repeatedly driving in similar areas, which is usually the case.
However, asking for the attributes directly in the route match request is more simple on client side, and only the data of the links along the route are actually transferred. Where this is important, attributes should be fetched directly with the route match call.