Please refer to this issue: https://github.com/modelica/VehicleInterfaces/issues/18

The problem is:

model myModel
  inner Road road;
end myModel;

model Road
VisualizeSimpleRoads simpleShape;
end road;

model VisualizeSimpleRoads
outer Road road;
end VisualizeSimpleRoads;

Is this possible?
I cannot find any clear statement into the Modelica Specifications.

In Dymola it seems that this can work!