A good way to handle that is to make sure they pick their lane at the start of the road (if you can). You do that by having no lane switching except at entrance intersection. Does not always work but does sometimes. Another trick he has used sometimes is 2 lane picking. Basically you can only 1 lane at a time. The thing will sometimes get confused and try cutting across 3 lanes of traffic holding up all 3 lanes. He usually stacks 2-3 of the 1 lane switches after each other and that sometimes clears it up.