Vehicle Size Restrictions & Pass Requirements — before you plan your drive, it’s important to know that Going-to-the-Sun Road has strict vehicle size limits and seasonal pass requirements. These rules protect the road, ensure safe driving on narrow, winding sections, and help manage summer visitor traffic. Ignoring them can lead to denied entry at park gates or hazardous situations on the alpine section.
Vehicle Size Limits
Due to tight curves, steep drop-offs, and narrow lanes, the park enforces size restrictions between Avalanche Creek and Rising Sun:
- Maximum length: 21 feet (6.4 m) including bumpers.
- Maximum width: 8 feet (2.44 m) including mirrors.
- Maximum height: 10 feet (3.05 m) from pavement to top of vehicle.
Vehicles exceeding these limits must use alternate routes (U.S. Highway 2 around the park) to reach the other side.
Why These Limits Exist
- Prevent collisions on blind, one-lane curves.
- Protect retaining walls and historic stone guardrails from large vehicle damage.
- Ensure smooth traffic flow in peak season.
Pass & Entry Requirements
In recent summers, the National Park Service has implemented a Vehicle Reservation System for Going-to-the-Sun Road during peak months (typically late May–early September). This is in addition to the standard park entry fee or pass.
- Timed Entry Pass: Valid for a specific day and entry window; book online in advance.
- Annual Pass Options: America the Beautiful Pass, Glacier National Park Annual Pass.
- Exemptions: Visitors with lodging, tours, or activity reservations inside the corridor may be exempt—check current rules.
Tips for Compliance
- Double-check rental vehicle specs before booking—some large SUVs or campervans may exceed limits.
- Secure your vehicle reservation early; spots can sell out within minutes when released.
- Print or save digital copies of passes; cell coverage is limited at gates.
Bottom Line
Knowing and respecting the size limits and pass rules ensures a safe, stress-free experience on Going-to-the-Sun Road, while preserving this engineering marvel for future visitors.