By passes are a type of road that allows some vehicles to avoid a congested area. The antonyms for by passes are main roads, city streets, or busy highways that are often heavily trafficked. Main roads are typically the most direct route between two points, and they usually have several lanes of traffic. City streets are typically narrower, and they are usually located in residential areas. Busy highways can be a mix of both main roads and city streets, but they are typically more congested due to the high volume of traffic. By passes are a useful tool for drivers who wish to avoid traffic congestion, but they are not always the best option.