Required Emergency Equipment and Where to Place Warning Triangles After a Breakdown

The direct answer: every truck and truck tractor must carry a mounted, charged fire extinguisher (5 B:C or more, or two rated 4 B:C or more; 10 B:C or more if the vehicle hauls placarded hazardous materials) and either three bidirectional reflective triangles or at least six fusees (49 CFR 393.95). When a truck stops on the traveled part or shoulder of a highway for anything other than traffic, the driver must turn on the hazard flashers immediately and place the warning devices within 10 minutes — one 10 feet behind on the traffic side, one 100 feet behind in the lane or shoulder, and one 100 feet ahead (49 CFR 392.22). Emergency equipment is also one of the eleven items a DVIR must cover.

What the power unit must carry

• Fire extinguisher — UL rating 5 B:C or more, or two extinguishers each 4 B:C or more; 10 B:C or more on a power unit transporting hazardous materials in placarded quantity. It must be labeled with its UL rating, show visually whether it is charged, be filled and readily accessible, and be securely mounted so it cannot slide, roll or move vertically. The agent must not need protection from freezing. An extinguisher rolling around the cab floor fails on mounting alone.
• Warning devices — three bidirectional emergency reflective triangles meeting FMVSS No. 125, or at least six fusees (plus as many more as the placement rules require). Other devices may be added but never substituted. Fusees must burn 30 minutes and carry the UL 912 mark; red flags, where used, must be at least 12 inches square on standards that hold them upright.
• No flame devices on vehicles carrying Division 1.1, 1.2 or 1.3 explosives, on cargo tanks for flammable gas or flammable liquid (loaded or empty), or on vehicles that run on compressed gas as motor fuel. Those trucks carry triangles.

The regulation no longer requires spare fuses as a separate item; a vehicle’s own overcurrent protection is covered elsewhere in Part 393. Carrying spares is still sensible — a blown fuse is a common cause of trailer lights going dark.

Where the triangles go

Situation	Placement toward approaching traffic	Also
Two-way road, normal visibility	One at 10 feet (4 paces) on the traffic side of the vehicle; one at 100 feet (40 paces) in the center of the lane or shoulder	One at 100 feet in the direction away from approaching traffic
Divided or one-way highway	One at 100 feet and one at 200 feet in the center of the lane or shoulder	One on the traffic side within 10 feet of the rear
Within 500 feet of a hill crest, curve or obstruction	The device on the obstructed side goes 100 to 500 feet out, far enough to give ample warning	Other devices as above
Business or residential district	Not required while lighted lamps are not required	Required at night when street lighting does not make the vehicle clearly visible at 500 feet

Hazard flashers go on immediately and stay on until the devices are placed, and again while they are picked up. If only fusees are carried, one must stay lit at each position for as long as the truck is stopped. Leaking fuel or any flammable liquid or gas means no flame-producing signal anywhere near it.

What this has to do with repair

A breakdown becomes dangerous in the first ten minutes, before anyone has arrived. Drivers who know the placement rule protect themselves and the responder; drivers who do not stand behind a truck on the shoulder of I-80 with the flashers as their only warning. Our roadside page covers what to do first and what can be fixed on the shoulder; the triangles come before the phone call.

Common questions

Can I carry LED flares or a beacon instead of triangles?

In addition to, not instead of. The regulation permits other devices that do not reduce the effectiveness of the required ones, but the three triangles (or six fusees) must be aboard and used.

Does the extinguisher need an inspection tag?

The federal rule requires the UL rating label, a visual charge indicator, and a charged, securely mounted unit; it does not itself require an annual service tag. Many fleets tag anyway, and an extinguisher with a gauge in the red fails the roadside check regardless of tag.

Is emergency equipment checked at the annual inspection?

It is on the driver’s daily report list and inspectors look for it at roadside. The periodic annual inspection focuses on the vehicle’s mechanical systems; carrying the equipment is a day-to-day obligation.

General guidance citing the Federal Motor Carrier Safety Regulations as published on eCFR, reviewed 2026-10-16. It is not legal advice; confirm specifics against the current regulation.