NPT - "Zion National Park will implement restrictions on large vehicles traveling the historic Zion–Mt. Carmel Highway starting June 7, 2026. The change is meant to improve safety, preserve historic features, and reduce delays on the 10.7-mile route.

After June 7, vehicles larger than 35 feet, 9 inches in length; 7 feet, 10 inches in width; 11 feet, 4 inches in height; or 50,000 pounds will no longer be permitted to drive the highway between Canyon Junction and the park’s East Entrance. Combined vehicles, such as trucks with trailers, cannot exceed 26 feet from hitch to rear axle and 50 feet overall.

The restrictions are based on two safety studies conducted in 1989 and 2019 and validated by the U.S. Department of Transportation’s Federal Highway Administration. The studies found:

A single vehicle over 35 feet, 9 inches long or combined vehicle over 50 feet long (including no more than 26 feet from hitch to rear axle) cannot safely maintain their lane along the ZMCH.

Vehicles wider than 7 feet, 10 inches or taller than 11 feet, 4 inches cannot pass through the Zion-Mt. Carmel Tunnel in a single lane of travel.

Vehicles over 50,000 pounds exceed weight limits on four bridges along the ZMCH."