CDL Road Signs Glossary (2026)

Stop

Full stop required. The only sign shaped like an octagon -- recognizable by shape alone, even at night or from behind.

Yield

Slow down and let cross traffic or pedestrians go first -- stop if needed to avoid a conflict.

Keep Right

Posted at a median or obstruction ahead — stay to the right of it.

Keep Left

Posted at a median or obstruction ahead — stay to the left of it.

One Way

Traffic on this street moves only in the direction the arrow points.

Trucks Use Right Lane

Commercial vehicles must stay in the right lane on this stretch, usually on long grades or multi-lane highways.

No Trucks

Commercial trucks are prohibited on this road -- find an approved truck route instead.

Truck Route

Marks a route designated for trucks, often routing commercial traffic around restricted areas.

Weigh Station — Mandatory

Trucks over the posted weight must exit and be weighed. Skipping an open weigh station is a violation in every state.

Runaway Vehicles Only

Marks the entrance to a runaway-vehicle ramp -- for emergency use only, not a shoulder or rest area.

Weight Limit

The maximum vehicle or axle weight allowed on this road or bridge.

Weight Limit — Per Axle and Gross

Posts two separate limits: the maximum weight per axle and the maximum gross vehicle weight allowed.

Accessible (Handicap) Parking

Reserved for vehicles displaying a valid disability placard or plate.

Stop Here When Flashing

Posted at a crosswalk or school zone with a flashing beacon — stop only when the light is actually flashing.

Pedestrian Push-Button Signal

Press the button to activate the crosswalk signal or extend your crossing time.

No Right Turn

Turning right is prohibited at this intersection, any time -- not just on red.

No Left Turn

Turning left is prohibited at this intersection, any time.

No Turn on Red

You may not turn right (or left onto a one-way street) against a red light at this intersection.

No U-Turn

Turning around to head back the opposite direction is prohibited at this location.

Wrong Way

You're heading against traffic on a one-way road or exit ramp — stop and reverse direction safely.

No Parking

Parking is prohibited here at any time.

Right Turn Only

From this lane, you must turn right — going straight or turning left is not allowed.

Left Lane Must Turn Left

A lane-control sign posted over or beside a lane — that lane can only go the way the arrow shows.

Railroad Crossbuck

Posted right at the tracks — not the same as the yellow round advance-warning sign. Treat it like a yield sign; stop if a train is coming (and remember: commercial vehicles carrying passengers or hazardous materials must stop at every crossing by law).

Do Not Enter

Wrong way. Stop, do not enter. Turn around safely.

Curve Ahead

The road bends the direction the arrow curves — slow down before entering it, especially with a loaded trailer.

Reverse Turn

A sharp turn one way immediately followed by a sharp turn the other way.

Reverse Curve

A gentler curve one way immediately followed by a curve the other way.

Winding Road

A series of turns ahead — expect a stretch of curves, not just one.

Hairpin Curve

An extremely sharp curve, close to a 180-degree turn — slow down well in advance, particularly for long combination vehicles.

Y-Intersection Ahead

The road splits into two ahead in a Y shape — decide your lane early.

Roundabout Ahead

A circular intersection ahead — yield to traffic already in the circle. Large trucks may need the full roundabout width.

Side Road Ahead

A minor road joins from the side — watch for vehicles entering from it.

Stop Ahead

A stop sign is coming up that you might not see in time -- start covering your brake early with a loaded trailer.

Yield Ahead

A yield sign is coming up — be ready to slow and let other traffic go first.

Signal Ahead

A traffic light is coming up, often around a curve or over a hill — be ready to stop.

Reduced Speed Limit Ahead

The speed limit drops ahead — start slowing now, not at the new sign.

Merge

A lane from the side is joining yours — traffic already on the road has the right-of-way.

Added Lane

A new lane is beginning — no one needs to merge, the road is simply widening.

Road Narrows

The roadway ahead is narrower than what you're on now — be ready to merge or slow down.

Narrow Bridge

A bridge ahead is narrower than the road leading to it — oncoming traffic may need to slow or wait, and wide loads should check clearance.

Divided Highway Begins

The road ahead splits into two separated roadways with a median between them.

Divided Highway Ends

The median ends ahead — oncoming traffic will be back in the lane next to you.

Two-Way Traffic

You're entering a section with opposing traffic in the next lane — usually right after a divided highway ends.

Steep Hill / Grade Ahead

A steep downgrade ahead — select a lower gear before you start down, not after. Runaway-ramp signage is common on long descents.

Truck Rollover Risk

A curve or ramp ahead has a documented risk of truck rollovers, usually due to speed and radius -- slow well below the posted advisory speed if you're high or top-heavy.

Runaway Truck Ramp Ahead

An emergency escape ramp for trucks with failing brakes is coming up on a long grade -- know the distance in case you need it.

Truck Escape Ramp

Marks the ramp itself, built to safely stop an out-of-control truck using loose gravel or an upgrade.

Truck Crossing

Trucks entering or crossing the roadway ahead, often near a quarry, plant, or freight yard.

Trucks Entering

A general warning that trucks may be entering or merging from the side ahead.

Slippery When Wet

The road surface loses traction in rain or ice — slow down and increase your following distance, especially with a loaded trailer.

Railroad — Round Advance Warning

Train tracks ahead. Look both ways; expect stopped traffic. Remember: buses and placarded hazmat vehicles must stop at every crossing.

Bicycle Crossing

Watch for cyclists crossing or sharing the road ahead — common near trails, parks, and bike lanes.

Pedestrian Crossing

A marked or expected foot-traffic crossing ahead — yield to anyone in the crosswalk.

Deer / Animal Crossing

A high-risk area for animals entering the road — most common at dawn, dusk, and near wooded areas.

Low Clearance Ahead

An overpass or tunnel ahead is lower than standard — the number is the maximum vehicle height. Know your rig's exact height before every trip.

No Passing Zone

Sideways triangle on the left of the road. No-passing zone begins -- give extra room given your vehicle's longer passing distance.

Road Work Ahead

A construction or maintenance zone ahead — expect lane shifts, workers, and reduced speed.

Detour

The normal route is closed ahead — follow the posted alternate path. Confirm the detour has no low clearances or weight limits your rig can't clear.

One Lane Road Ahead

The road narrows to a single lane shared by both directions — yield as needed.

Lane Closed Ahead

One travel lane ends ahead — merge into the open lane before it disappears, earlier than a passenger car would need to.

Flagger Ahead

A worker with a stop/slow paddle is directing traffic — their signal overrides the posted rules.

School Zone

5-sided fluorescent yellow-green sign marking a school zone or school crossing.

Weigh Station Ahead

Advance notice that a weigh station is coming up -- the mandatory black-and-white regulatory version tells you whether you must enter.

Truck Parking

Truck parking is available nearby.

Brake Check Area

A pull-off for checking your brakes before a long, steep downgrade -- use it, don't skip it.

Chain-Up Area

A pull-off for putting on or removing tire chains in winter conditions.

Interstate Route Shield

Blue-and-red shield marks a numbered interstate highway — the same shape and colors nationwide.

US Route Marker

A black-and-white shield marks a numbered U.S. highway, distinct from state and interstate routes.

State Route Marker

Marks a state highway. Unlike interstate and US-route shields, the exact shape varies by state — this is one common style.

Airport

Blue guide sign pointing the way to the nearest airport.

Parking Area

Directs you to a designated parking area.

Park & Ride

A lot where you can park and switch to a bus, train, or carpool.

Rest Area

A highway rest stop ahead with parking and restrooms.

Picnic Area

A roadside picnic area or roadside park ahead.

Scenic Area / Overlook

A scenic view or overlook pull-off ahead.

Interstate Oasis

A combined rest stop and services area built into the highway median.

Telephone

A public or emergency telephone is available nearby.

Hospital

Directs you to the nearest hospital.

Camping

A campground is available nearby.

Litter Container

A trash receptacle is available at this stop.

Gas

Fuel is available nearby.

Food

A restaurant or food service is available nearby.

Lodging

A hotel or motel is available nearby.

Tourist Information

A visitor or tourist information center is nearby.

Diesel Fuel

Diesel fuel is available nearby.

Electric Vehicle Charging

An EV charging station is available nearby.

RV Sanitary Station

An RV waste-dumping station is available nearby.

Emergency Medical Services

Emergency medical services are available nearby.

Police

A police station or post is available nearby.

Pharmacy

A pharmacy is available nearby.

Telecommunication Device for the Deaf

A TDD/TTY phone for the deaf and hard of hearing is available nearby.

Wireless Internet

Wi-Fi internet access is available at this stop.

Radio Traffic/Weather Info

Tune to the posted AM station for local traffic or weather updates.

Carpool Information

Directs you to carpool program information.

Emergency Call Station

A roadside call box for reporting emergencies.

511 Travel Info

Call 511 for real-time road conditions and traffic info.

Roadside Assistance

Directs you to roadside assistance services.