A bypass road is a road or highway that avoids a built-up area, town, or village, allowing through traffic to flow without interference from local traffic. The purpose of a bypass road is to reduce congestion in the built-up area and improve road safety)). Bypass roads are also constructed to direct motorists around a city or central business district, linking from an existing road to another road. In the United States, bypass routes are a type of special route used on an alternative routing of a highway around a town when the main route of the highway goes through the town. The original designation of these routes was "truck routes" to divert through truck traffic away from the town, but the designation was changed to "bypass" in 1959 by AASHTO). Bypass roads are common in rural municipalities to deter through traffic from entering the poblacion).