How to avoid low-clearance bridges in an RV

Low-clearance strikes are common, expensive, and almost entirely avoidable. Car navigation doesn't know your rig is twelve or thirteen feet tall, so it will route you straight at an underpass it thinks is fine. Avoiding that comes down to three things: knowing your true height, understanding where low bridges hide, and using routing that actually accounts for both.

1. Know your rig's true height — to the inch

You can't avoid a clearance you've measured wrong. Measure from the ground to the single highest point on your rig — usually the roof air conditioner, sometimes an antenna, vent, or satellite dome. Manufacturers frequently list height without the A/C, so the number on the spec sheet is often too low. Most RVs come in at or under 13 feet 6 inches, the practical ceiling many older structures were built to — but "most" isn't "yours," so measure.

Then give yourself margin. Repaving can add height to the road and quietly steal an inch or two of real clearance, and posted signs aren't always exact. Routing as if your rig were an inch or two taller than it is costs you nothing and keeps the margin on your side.

2. Learn where low bridges hide

The danger is rarely the Interstate — new Interstate construction targets at least 16 feet of clearance. It's everything else: older secondary roads, rail overpasses, historic downtowns, and especially parkways in the Northeast, many of which were designed for cars only and ban trucks and RVs outright. When a route drops you off the Interstate onto a scenic parkway or a shortcut through an old town, that's when clearance matters most.

The 11-foot-8 lesson

The most-watched low bridge in America is the "can-opener" — the Norfolk Southern–Gregson Street overpass in Durham, North Carolina. For decades it cleared just 11 feet 8 inches and racked up a famous highlight reel of box trucks losing their roofs. In October 2019 it was raised to 12 feet 4 inches — and vehicles still hit it. The takeaway isn't about one bridge: it's that low clearances exist well below the legal maximum height, and posted-clearance data alone won't save you. You need routing that actively keeps you away from them.

3. Route with something that knows your height

This is the part car apps can't do. RV-safe routing takes your rig's height (and width, length, weight, and propane) and steers around low clearances, weight-limited bridges, and restricted tunnels before it ever shows you the route. The clearance data comes from state and local DOT databases, field surveys, and RVer reports, and good routing uses the lowest posted value to stay conservative.

RV Compass does exactly this — and then shows its work, listing each low bridge or restriction it routed you around so you can see why the route bends. Community hazard reports catch the clearances the map data missed and feed them back into everyone's routing.

Your low-bridge avoidance checklist

1. Measure your true height to the highest point, including the roof A/C.
2. Add an inch or two of safety margin and route with that number.
3. Plan with RV-safe routing — never a plain car map.
4. Watch for parkways and truck/RV bans, especially in the Northeast.
5. Read posted clearance signs as you go, and believe the lowest number.
6. Keep a dedicated low-clearance map or RV GPS as a backup.
7. If a clearance looks marginal, turn around — the detour always beats the roof.

Let RV Compass watch the bridges for you

Set your rig's height once and every route is computed to keep you clear of low bridges automatically, with each avoided clearance explained. It's the whole reason RV Compass exists.

Keep reading: the full guide tobig-rig route planning, or see how RV Compass compares in our comparison with RV LIFE Trip Wizard.