What is the required clearance over an interstate highway?

The correct answer is 17 feet. This clearance height is established to ensure safety for vehicles traveling on interstate highways, including trucks and other larger vehicles. The Federal Highway Administration (FHWA) sets this standard to avoid any accidents or damages that may occur if vehicles were to collide with low-hanging structures, such as bridges or overpasses.

To put this into perspective, standards vary depending on the type of road and the traffic it accommodates. An elevation of 17 feet is deemed sufficient for most vehicles, including those used for freight hauling, which are often among the tallest on the road. Maintaining this clearance minimizes the risk of incidents while ensuring compliance with national transportation regulations. Thus, the 17-foot clearance serves to safeguard both motorists and infrastructure along interstate routes.