We are building mobile application for truck navigation. When using HERE SDK route calculation for trucks, it sometimes tries to avoid a particular road segment, that is in reality suitable for trucks.
One example - highway crossing:
When I calculate route for car, route is correct and meaningful, it follows the highway from south to the north and crosses under the east-western highway. We expect the same route also for a truck as trucks drive like this daily basis (legally).
But when we actually calculate route for truck, it makes a massive detour and takes us either to the westbound highway (blue route on the picture) or eastbound highway, where it turns back after several kilometers and comes back (green route on the picture), both of which is a nonsense. It seems as HERE wants to avoid going under the highway bridge.
I tried to put a waypoint slightly north of the east-western highway and suddenly even with truck setting the route is calculated correctly and does no longer want to avoid going under the bridge. So it seems HERE knows it is legal to go there, but tries to avoid this particular road segment at all costs. We witnessed such behavior multiple times at different places.
This is the exact setup:
- Start:
49.154356, 16.600705 - Destination:
49.190870, 16.594660 - Traffic is disabled for route calculation
- For tta time we use
getTtaExcludingTraffic() - Truck dimensions were tested both with zero size and and with very small values, so that it certainly fits under the bridge
Question is what causes this behavior? It is a problem of HERE's data? Can we avoid such detours in our application?