What vertical clearance do Interstate design standards call for?

Interstate design standards generally call for 16 feet of vertical clearance, with 14 feet allowed in urban areas where an alternate 16-foot route exists (23 CFR Part 625).

What is the maximum legal height of a standard commercial trailer?

Standard interstate dry van and refrigerated trailers measure 13 feet 6 inches (13.5 ft). High-cube and specialized containers can reach 14 feet 0 inches. Legal height limits are set by each state; check the state’s oversize rules for your route.

What are the consequences of striking an overhead structure?

Striking an overhead structure can cause serious damage and legal liability.

Low-Clearance Tunnel Directory

Filter low overhead clearances, posted weight limits and hazardous material restrictions for highway tunnels, by clearance height, state or route. Records come from the FHWA National Tunnel Inventory.

FHWA 23 CFR 650

Maximum Truck Height Clearance Threshold

Structure or route

State

Hazmat restricted

Showing 0 structures under 13.5' clearance nationwide

Source: FHWA National Tunnel Inventory

Querying Federal Highway Administration inventory records…

Federal Overhead Clearance & Hazmat Mandates

Standard interstate 53-foot dry vans and refrigerated trailers measure 13 feet 6 inches in factory outer height. When unladen, tire inflation pressure and suspension rake can lift the trailer roof by up to 3 inches. Tunnels posted under 14 feet 0 inches require cab confirmation and route verification.

Critical Strike Danger (< 13' 6"): Structures measuring below 13 feet 6 inches will result in an immediate impact collision with standard interstate commercial semi-trailers. Commercial GPS navigation rerouting or local highway patrol escort is required.
Hazardous Materials Restrictions: Tunnels with the Hazmat Prohibited designation strictly forbid Class 1 (Explosives), Class 2 (Flammable Gas), and Class 3 (Flammable Liquids) cargo under 49 CFR Part 397. Violations carry state impound and federal safety citations.

Frequently Asked Questions About Tunnel Clearances

What vertical clearance do Interstate design standards call for?: Interstate design standards generally call for 16 feet of vertical clearance, with 14 feet allowed in urban areas where an alternate 16-foot route exists (23 CFR Part 625).
What is the maximum legal height of a standard commercial trailer?: Standard interstate dry van and refrigerated trailers measure 13 feet 6 inches (13.5 ft). High-cube and specialized containers can reach 14 feet 0 inches. Legal height limits are set by each state; check the state’s oversize rules for your route.
What are the consequences of striking an overhead structure?: Striking an overhead structure can cause serious damage and legal liability.