Utah Highway 9
Zion-Mt. Carmel Hwy and Mt. Carmel Scenic Byway
The Zion Mt. Carmel Highway (SR-9), the road in and through Zion National Park does not ever close and is traveled in your personal vehicle, but large campers, RV's and busses must only travel this road when escorts are present. See the information below for oversized vehicles. A fee is required even if you are just passing through the park. If you are not interested in seeing Zion you can detour in Hurricane and take AZ-389 to
US-89. For those that have a high clearance, reliable vehicle, you could even cut through the Coral Pink Sand Dunes, depending on your destination.
Map
The Zion Canyon Scenic Byway is a short 6-mile road that the Zion Canyon shuttle travels, taking visitors into Zion Canyon most of the year. In the winter, when the shuttle shuts down, then you can drive your personal vehicle into the canyon.
Oversized Vehicle Information - Zion-Mt. Carmel Tunnel Escort
An escort fee is required for vehicles 7'10" wide and/or 11'4" tall or larger which usually includes all RV's, buses, trailers, 5th wheels, dualie trucks, and some camper shells. Escorts (rangers) are stationed at both sides of the Zion-Mt. Carmel
Tunnel to direct traffic. During
winter months, escorts are arranged at the entrance stations. The hours are posted seasonally at kiosks before you enter the park from either direction, but it usually late March through late October, escorts are usually stationed at the tunnel from 8am to 8pm daily and in November the time shortens to 8am to 4:30pm. The $15 fee is good for two trips through the tunnel within 7-days.
Zion National Park roads ...more good stuff @ the link