public boolean assertInvariant() {
final RoadMapping roadMapping = roadMapping();
if (roadMapping != null) {
assert roadMapping.laneCount() == laneCount();
assert roadMapping.trafficLaneMax() == trafficLaneMax();
assert roadMapping.trafficLaneMin() == trafficLaneMin();
assert Math.abs(roadMapping.roadLength() - roadLength()) < 0.1;
}
for (final LaneSegment laneSegment : laneSegments) {
laneSegment.assertInvariant();
}