About Identifying Turn Restrictions

Trapeze routing algorithms are intersection-based. Vehicles can turn at any intersecting street segments that are split at the intersection. For this reason, Trapeze recommends that overpass segments should not be split at points where streets pass under them.

To specify physical turn restrictions or legislated turn restrictions that apply at all times, MapMaker can load end-point values, or z-levels, that indicate planar connectivity. If intersecting segment end-points have different z-level values, vehicles can not turn from the one segment to the other at the intersection. If intersecting segment end-points have the same z-level values, vehicles can travel from the one segment to the other.