Before revision: When traffic is especially heavy on a highway or main road, rat-running vehicles may cause another traffic jam on the rat-run streets, along with accompanying problems such as collisions, pollution from exhaust, or road rage.
After revision: When traffic is especially heavy on a highway and main road, rat-running vehicles may cause another traffic jam on the rat-run streets, along with accompanying problems such as collisions, pollution from exhaust, or road rage.