DOT Out-of-Service Criteria for Trucks: A Driver’s Guide

What “out of service” means

During a roadside inspection, inspectors check the vehicle against the North American Standard Out-of-Service Criteria, published by the Commercial Vehicle Safety Alliance (CVSA). A violation of those criteria means the vehicle — or the driver — is placed out of service and can’t operate until the problem is corrected.

Not every violation is an out-of-service violation. An inspector can write up a defect as a regular violation, which still counts against the carrier’s safety record, without parking the truck. The out-of-service criteria mark the line where a defect is serious enough that the truck shouldn’t move.

CVSA updates the criteria regularly, with new editions typically taking effect each April 1. This guide gives common examples in plain language; the current official criteria are what inspectors actually use.

Brakes

Brakes are consistently among the most common reasons trucks are placed out of service. Examples of brake conditions that can trigger an out-of-service order:

Too many defective brakes. When 20 percent or more of the service brakes on a vehicle or combination are defective — including brakes out of adjustment — the vehicle is out of service.
Steering axle brakes that are inoperative or have certain defects.
Air leaks, such as an audible leak at a brake chamber, or air loss beyond the allowed limits.
Damaged components — broken or missing brake parts, cracked drums, and linings contaminated with oil or grease or worn past limits.
Air supply problems that affect the system’s ability to build and hold pressure.
Tractor protection and breakaway systems that don’t work as required.

Pushrod stroke past the adjustment limit for the chamber size is a very common find. Depending on how far past the limit it is, an out-of-adjustment brake counts as a full or partial defective brake toward the 20 percent rule.

Tires and wheels

Steer tires with less than 2/32 inch of tread in any two adjacent major tread grooves.
Other tires with less than 1/32 inch of tread in two adjacent major grooves at multiple locations.
Flat tires, or tires with an audible leak.
Exposed belt or ply material through the tread or sidewall.
Tires touching another tire or part of the vehicle.
Wheels and rims with cracks, or loose, missing, or broken lug nuts and studs beyond allowed limits.

The federal maintenance rules set higher tread depth minimums — 4/32 inch on steer tires and 2/32 inch on other tires — so a tire can earn a violation well before it reaches the out-of-service level.

Lights and reflectors

Lighting problems are among the most common vehicle violations overall. For out-of-service purposes, the criteria focus on the lights that matter most for being seen and signaling — for example, when required stop lamps or rear turn signals on the rearmost vehicle don’t work, or when required lamps are out during darkness or poor visibility.

A single burned-out marker lamp usually won’t park a truck, but it’s still a violation — and an easy fix. Walk around the truck with the lights and flashers on during every pre-trip.

Suspension, frame, and coupling

Leaf springs with a quarter or more of the leaves in any spring assembly broken, or a broken main leaf.
Air suspension that’s deflated or has damaged air springs.
Torque rods, U-bolts, and spring hangers that are broken, missing, or loose enough to let the axle shift.
Frame cracks and broken frame members beyond allowed limits.
Fifth wheel and coupling defects, including locking jaws that don’t close properly and mounting problems.

Other common categories

Cargo securement that doesn’t meet requirements or lets cargo shift.
Fuel system leaks — dripping fuel from tanks, lines, or fittings.
Exhaust leaks that can put fumes into the cab or sleeper, or exhaust parts positioned where they could burn wiring, fuel lines, or cargo.
Steering — excessive steering wheel lash, and loose or damaged steering components.
Driver issues, which are separate from vehicle defects — hours of service, license, and medical certificate problems.

How to stay in service

Do a real pre-trip. Walk around with the lights and flashers on, check tires and wheels, listen for air leaks, and look at brake chambers and slack adjusters.
Fix defects when they’re found, not the next time the truck happens to be at a shop.
Keep annual inspections current and use them to catch wear early. See mobile DOT inspections.
Stay on top of preventive maintenance. See fleet PM service.

If a truck is placed out of service, a mobile mechanic can often correct the defects right where it was stopped. Keep the inspection report — it lists exactly what has to be fixed.

General information only. This guide is written for drivers and dispatchers working the Port of Los Angeles and Port of Long Beach. Regulations change and every truck is different — when in doubt, follow your carrier's procedures, the current FMCSA and CARB regulations, the terminal operator's rules, and the instructions of law enforcement on scene.

DOT Out-of-Service Criteria: What Gets a Truck Parked