Truck and trailer rules in Utah: licence classes, safety chains, size limits and oversize permit fees

This page reports what the official source says. It is not legal advice: ask the office named here. All of the sources are chapters of the Utah Code, published on the Utah Legislature website: the Traffic Code, the driver licence chapter and the chapter on vehicle size, weight and load. Federal background and the other places are on the parent page, trucks and trailers for tree work.

At a glance

Item	What the sources say
Commercial motor vehicle	Rating or weight of 26,001 pounds or more, single vehicle or combination
Class A	Combination rated 26,001 pounds or more when the towed vehicle is rated over 10,000 pounds
Class B	Single vehicle rated 26,001 pounds or more, including when towing a vehicle rated 10,000 pounds or less
Trailer brakes	A stopping-distance standard for the whole combination; no trailer weight line in the section read
Safety chain	Required on a towed vehicle in addition to the hitch, with listed exceptions
Width, height	8 1/2 feet wide; 14 feet high
Length	45 feet single-unit vehicle; 65 feet for most other combinations
Gross weight	80,000 pounds for a vehicle or combination, with axle limits
Oversize permit fee	US$30 single trip, US$75 semiannual, US$90 annual
Carrier number	Not published on the pages read

Licence classes

The driver licence chapter defines a commercial motor vehicle as a motor vehicle or combination designed or used to carry passengers or property that has a gross vehicle weight rating or gross vehicle weight of 26,001 or more pounds, or a combination rating or weight of 26,001 or more pounds, or a lesser rating set by federal regulation. A vehicle built for 16 or more passengers, and one carrying placarded hazardous materials, also counts. A class D licence is the class for motor vehicles that are not commercial motor vehicles or motorcycles. For the commercial classes, the chapter says class A is any combination of vehicles rated 26,001 pounds or more where the vehicle or vehicles being towed are rated over 10,000 pounds. Class B is any single motor vehicle rated 26,001 pounds or more, including that vehicle towing a vehicle rated 10,000 pounds or less. Class C is a single vehicle under 26,001 pounds, or one towing a vehicle of 10,000 pounds or less, that is built for 16 or more passengers, is a school bus, or carries placarded hazardous materials. The fee section lists a class D original licence at US$52. See chapter 3 of Title 53 on driver licences.

Brakes and safety chains

Section 41-6a-1623 of the Traffic Code sets brakes by performance. A motor vehicle and a combination of vehicles must have a service braking system that stops the vehicle or combination within 40 feet from 20 miles per hour on a level, dry, smooth, hard surface, or a shorter distance the department sets under federal standards. The parking brake must hold the vehicle or combination on any grade it is operated on under all conditions of loading. The section read does not name a trailer weight at which trailer brakes begin. A violation is an infraction.

Section 41-6a-1634 says a towed vehicle must be coupled by a safety chain, cable or equivalent device in addition to the regular hitch or coupling. It must be securely connected to the chassis of the towing vehicle, the towed vehicle and the drawbar, be strong enough to keep the two vehicles from separating, have no more slack than turning needs, and be attached so the drawbar cannot drop to the ground. The rule does not apply to a semitrailer with a fifth wheel and king pin, a pole trailer, or a trailer towed by a bicycle. A violation is an infraction. The pages read do not mention a breakaway device. See chapter 6a of Title 41, the Traffic Code.

Width, height and length

Section 72-7-402 says a vehicle, unladen or with a load, may not exceed 8 1/2 feet in width or 14 feet in height. A single-unit vehicle may not exceed 45 feet including bumpers. A semitrailer may not exceed 53 feet. Two trailers coupled together may not exceed 61 feet overall. All other combinations of vehicles may not exceed 65 feet in total, apart from night emergency repair by a public utility and vehicles under a permit. Safety devices and hitches that do not carry cargo are left out when width and length are measured. A load may not extend more than three feet past the front of the body or six feet past the rear of the bed or body. Section 72-7-403 limits the draw-bar or other connection between a towing and a towed vehicle to 15 feet from one vehicle to the other, and a chain, rope or cable connection must show a red flag of at least 12 inches by 12 inches near its midpoint. Section 72-7-404 sets a gross weight of 80,000 pounds for a vehicle or combination, 20,000 pounds on a single axle and 34,000 pounds on a tandem axle, with a bridge formula for axle groups.

Oversize permits

Under section 72-7-406 the department may, on an application and good cause, issue a written oversize permit for a vehicle or combination that exceeds the width, height or length limits, and the department approves the route first. The application states the vehicle sizes, the roads and whether the permit is for a single trip. The permit must be in the vehicle, and an electronic copy is accepted as proof. For the size permits in subsection 5 the fees are US$30 for a single trip valid up to 96 continuous hours, US$75 for a semiannual permit valid up to 180 continuous days, and US$90 for an annual permit valid up to 365 continuous days. Only a single trip permit is issued for a vehicle more than 14 feet 6 inches wide, 14 feet high or 105 feet long, apart from the annual permits the department sets by rule. See chapter 7 of Title 72 on size, weight and load.