Hi there !
This article might provide useful info on building route planning apps for trucks. https://developer.tomtom.com/blog/build-different/how-schedule-routing-truck-drivers
The Routing engine can take different parameters into account when vehicle type Truck is selected: type of cargo, vehicle dimensions, weight, etc. Based on this input it will try to calculate a safe and compliant route for that vehicle. It will avoid bridges and tunnels that do not fit this vehicle, roads with restrictions for vehicle or cargo types. It will also try to minimize manoeuvers that are complex for large vehicles, such as sharp turns or narrow roads. In some cases this can result in a route that is very different than that of a normal passenger car.
You might also want to try the Eco mode in routing, which is designed to find fuel-efficient routes.