RouteAllOversize Load Equipment: Flags, Banners, Lights
Last verified September 8, 2026 against 49 CFR 393.87 and the four state rules linked below.
Three pieces of equipment mark an oversize load: flags at the corners, an OVERSIZE LOAD banner front and rear, and warning lights. Federal rule sets one number, 18 inches square for a flag. Everything else is set by the state.
This guide names four states and links each rule.
In one minute: buy flags first, because the federal size is the same everywhere. Buy the banner second, and buy the larger one. A 7-foot banner with 10-inch letters satisfies Oklahoma's smaller minimum, but a 5-foot banner does not satisfy Rhode Island.
Lights are the piece that varies most, and the permit is where you read the answer.
What size flags do you need?
At least 18 inches square, in red or orange fluorescent. That is the federal floor in 49 CFR 393.87 and it applies to any commercial vehicle whose load projects past the sides or the rear. Every state rule in this guide repeats the same 18-inch number rather than raising it.
"Any commercial motor vehicle transporting a load which extends beyond the sides by more than 102 mm (4 inches) or more than 1,219 mm (4 feet) beyond the rear must have the extremities of the load marked with red or orange fluorescent warning flags." — 49 CFR 393.87(a). Verified September 8, 2026.
The federal rule also sets how many flags go on a projection. One flag if the end of the projection is two feet wide or less, two flags if it is wider.
Where do the flags go?
On the extremities of the load, meaning the widest and rearmost points. That is often past the corners of the trailer itself, so measure the load and not the deck. South Dakota goes further and flags all four corners of the vehicle once it passes 8 feet 6 inches wide.
- Four inches of side projection triggers federal flags, which is less than most drivers expect.
- Four feet of rear projection triggers them as well.
- Three feet of front projection triggers flags in South Dakota and Utah.
- Clean and untorn is a Utah requirement: flags must be fastened to wave freely.
How big must the banner be?
It depends on the state, and the spread is wide. Oklahoma accepts a banner 5 feet long and 14 inches high with 8-inch letters. Rhode Island and Utah both require 7 feet by 18 inches with 10-inch letters. Buy to the larger specification and you satisfy all three.
Every state in this guide uses black letters on a yellow background.
| State | Banner size | Letter height | Source |
|---|---|---|---|
| Oklahoma | At least 5 feet by 14 inches | At least 8 inches | OAC 730:50-5-15 |
| Rhode Island | At least 7 feet by 18 inches | At least 10 inches | 290-RICR-40-00-1.5 |
| Utah | 7 feet by 18 inches | 10 inches | Utah Admin. Code R909-2-20 |
The table covers three states.
The oversize load sign requirements by state guide compares twelve states. For every other state on your route, read the permit and the state rule.
Rhode Island also sets a smaller banner for the escort vehicle, 5 feet by 12 inches. The escort banner and the load banner are not the same size.
A banner that is legal in Oklahoma does not meet the Rhode Island minimum. You must not assume one banner clears every state.
When is a banner required at all?
Oklahoma requires one on every oversize vehicle moving under permit, and forbids displaying one on a legal-size vehicle. Utah sets numeric thresholds instead: 10 feet wide, 14 feet 6 inches high and 105 feet long. The rule joins them with "and", so read your own permit for the trigger.
That difference matters at 9 feet wide. In Oklahoma the banner goes up because a permit was issued, while in Utah the load has not yet reached the 10-foot trigger.
Take the banner down when you run legal. Oklahoma, Rhode Island and Utah all require it.
What lights are required?
Lights vary more than flags or banners. Rhode Island requires no special light on the load vehicle and only low-beam headlights. Utah requires low beams day or night, red clearance lights on a rear overhang past 4 feet, and a beacon in some overhang cases. Your permit names the rest.
- Low beams are required day and night in Utah as an extra warning to traffic.
- Red clearance lights mark a rear overhang over 4 feet for night travel in Utah.
- A rotating beacon visible from 500 feet is required in Utah for overhang past 20 feet, mounted at least 4 feet up.
- No beacon is required on the Rhode Island load vehicle; the escort carries the flashing yellow light instead.
Amber warns from the front and sides, red from the rear. That convention holds in the rules above, but you must confirm the color and count on the permit for your state.
The escort's lighting is a separate rule set. The pilot car requirements by state guide covers the escort side.
What should you buy first?
Buy flags first, then banners, then a beacon. Flags are 18 inches square everywhere, so they never need replacing at a state line. Banners are where the money goes wrong: buy 7 feet by 18 inches with 10-inch letters and you clear every state in this guide.
Buy in this order and you will not buy twice.
- Flags. Eight of them, 18 inches square, red or orange fluorescent. The federal size does not change across state lines.
- Banners. Two, at 7 feet by 18 inches with 10-inch black letters on yellow. This clears the largest minimum in this guide.
- An amber beacon visible from 500 feet, mountable at 4 feet or higher.
- Spare flags. Utah requires flags that are clean, untorn and unfaded, and a road-worn flag fails that test.
RouteAll reads the permit you upload and drives the route it names, so the equipment conditions printed on that permit travel with the route. It does not inspect your rig.
Only the permit and the state rule decide what you must hang on the load.
Before you roll
Flags are the one number that is the same everywhere: 18 inches square, red or orange fluorescent. Banners and lights change at every state line, and the spread between Oklahoma and Rhode Island is 2 feet of banner and 2 inches of letter. Buy to the larger specification, then read the permit for the state you are entering.
Common questions
How big does an oversize load flag have to be?
At least 18 inches square, in red or orange fluorescent, under 49 CFR 393.87. Oklahoma, South Dakota and Rhode Island all repeat that same 18-inch minimum in their own rules. No state in this guide requires a larger flag, so one set of flags travels with you.
Can one banner satisfy every state?
Only if you buy the largest. Oklahoma allows 5 feet by 14 inches with 8-inch letters. Rhode Island and Utah require 7 feet by 18 inches with 10-inch letters. A 7-foot banner meets all three, but a 5-foot banner fails two of them.
Do I need an amber beacon on the truck?
It depends on the state and the overhang. Rhode Island requires no special light on the load vehicle at all. Utah requires a beacon visible from 500 feet when overhang passes 20 feet, mounted at least 4 feet above ground. Read the permit for your state.
Are flags required if the load fits on the trailer?
Sometimes, because width alone can trigger them. South Dakota requires flags at every corner once the vehicle or load is wider than 8 feet 6 inches, whether or not anything projects. The federal rule triggers on projection instead, at 4 inches to the side.
Further reading
Sources
- 49 CFR 393.87, warning flags on projecting loads.
- Oklahoma, OAC 730:50-5-15, "Oversize Load" sign and warning flags.
- Rhode Island, 290-RICR-40-00-1.5, safety requirements for nondivisible permits.
- South Dakota, ARSD 70:03:01:14, warning flags required for oversize movement.
- Utah, R909-2-20, oversize non-divisible load lighting, signing and flag requirements.
RouteAll reads the permit you provide. It does not issue permits or guarantee compliance. The driver remains responsible for the load. Only four states were verified for this guide; rules change, so verify against the permit and the issuing state before every move.