Low bridges and truck routes in NC cities: a driver's guide

The short version

North Carolina's legal height limit is 14 feet, loaded or empty. But the same law says no one has to raise a bridge, wire or other structure for a vehicle taller than 12 feet 6 inches. [1]

If your truck is over 12 feet 6 inches, the owner or driver is liable for any damage it does to a structure. A standard 13-foot-6 van is over that line. [1]

Signs and truck GPS help, but FMCSA says truck GPS is not a complete answer because many low overpasses are missing from navigation databases. Know your height, and obey the sign. [29][28]

How low clearances are signed

The national sign manual, the MUTCD (11th edition, December 2023), requires a Low Clearance sign when clearance is under 14 feet 6 inches, or under 12 inches above the state's legal height, whichever is greater. [14]

With NC's 14-foot limit, that 12-inch rule works out to clearances under 15 feet. That is simple math from the two rules, not a published NCDOT figure. [1][14]

Under MUTCD guidance, the sign shows the actual clearance to the nearest inch and should not exceed it. In areas where frost heaves the road, it may read up to 3 inches lower. [14]

That is a small cushion. The same guidance says clearances should be re-checked from time to time, especially after repaving, because new pavement raises the road and cuts the room underneath. [14]

Arched or uneven structures can be lower at the edges. The MUTCD lets agencies mount a sign over a lane or shoulder where clearance is not the same across the whole bridge. [14]

The older 2009 MUTCD only required the sign under 12 inches above legal height, so some older NC signs may follow that rule. [15]

NCDOT's posted bridge maps are about weight limits, not height. Don't read a missing weight posting as a clearance check. [34]

Durham's Gregson Street bridge

The best-known low bridge in NC is the North Carolina Railroad Company overpass on Gregson Street in downtown Durham. Local news long called it the "can opener" bridge. [9][10]

In October 2019 the railroad raised it 8 inches, from 11 feet 8 inches to 12 feet 4 inches. The $500,000 job was paid for by the railroad company. [9][10][11]

A railroad official told WRAL the 8 inches was the most it could gain without changing the grade of the nearby track. So the bridge is unlikely to go higher soon. [10][11]

NCDOT added a laser-triggered red light and warning sign in 2016. The News & Observer reported NCDOT figures showing crashes fell from 8.4 a year before the light to 3.6 a year from March 2021 to May 2023. [12]

Trucks still hit it. A Penske moving truck struck it in January 2020, about two months after the raise. At 12 feet 4 inches, it is still lower than a standard van trailer. [33][12]

Interstate overpasses get hit too

Low clearances are not only an old-downtown problem. In August 2023 an unknown northbound vehicle struck the Pope Road bridge over I-95 at Exit 72 in Dunn and did not stop. [32]

That bridge has 14 feet 6 inches of clearance, so the vehicle was over NC's legal height. Its steel girders were damaged and the bridge was closed for inspection. It had also been hit that May. [32][1]

FMCSA's research page on low-clearance detectors cites national truck bridge strikes of roughly 6,000 a year in 2005 to 2008. That is old data, but it shows the problem is common. [29]

Anything over 14 feet is over NC's legal height. See this site's guide to NC oversize and overweight permits before hauling a tall load. [1]

If you hit a bridge: stop and report it

Under G.S. 20-166, a driver who knows or should know about a property-damage crash must stop right away. Willfully leaving is a Class 1 misdemeanor. If anyone is hurt, leaving becomes a felony. [3]

You must give your name, address, license number and plate to the owner of the damaged property. If the property is a fixed object owned by NCDOT or a utility and no one can take a report at the scene, tell the nearest officer or mail a report to DMV by certified mail within 5 days. [3]

A crash with $1,000 or more of property damage is a reportable crash in NC. The driver must call the police, or the Highway Patrol or sheriff outside a city, by the quickest means. [5][4]

A bridge strike can be reportable under NC law even if the truck drives away. FMCSA's definition of an accident for the carrier's accident register is narrower: a death, an injury treated away from the scene, or a vehicle towed for disabling damage. [5][31]

53-foot trailers and the NC truck network

G.S. 20-115.1 lets tractors with trailers up to 53 feet run on NC's primary highway routes if they meet the kingpin and other conditions. NCDOT can bar them from parts of a route after a traffic engineering study. [2]

Doubles with two 28-foot trailers are limited to interstates and federally designated routes. [2]

These trucks get reasonable access to terminals, and to food, fuel, repairs and rest within three road miles of an interstate or designated highway. Terminals farther away need NCDOT approval of the route. [2][16][17]

That access right is about length and width, not height. NCDOT's truck network map and its truck restriction table, dated March 5, 2024, list route limits, but the table has no low-clearance entries. [19][20]

The table lists about 230 state-road ordinances. Examples include no through trucks on NC 157 and NC 751 in Durham County, and on US 76 from US 17 to Wrightsville Beach in New Hanover County, as of March 2024. [20]

"No through trucks" still lets you make a delivery on that road. For questions, NCDOT's truck access page lists 919-814-5000. [20][18]

City truck routes: Raleigh, Durham, Charlotte, Greensboro, Winston-Salem

Cities control their own streets, except roads on the state system. And under 49 CFR 392.2, a truck must follow the local laws and ordinances where it is running, even on an interstate trip. [21][30]

Raleigh routes through trucks on numbered Interstate, US and NC routes plus the Wade Avenue Extension. Local and visiting trucks stay on truck routes to the point nearest their destination. [22]

Raleigh's code also still bars vehicles over 13 feet 6 inches and combinations over 55 feet from city streets on weekdays from 7:30 to 8:30 a.m. and 4:30 to 6 p.m. How the city enforces this is not known. [22]

Durham defines a truck as 3 or more axles, or 2 axles at 18,000 pounds GVWR or more. Off a truck route, the driver must carry a bill of lading or other proof of origin and destination. Not having it is a misdemeanor. [23]

Charlotte bans through trucks inside the I-277/I-77 loop except on Graham Street, Brooklyn Village Avenue, McDowell Street and 11th Street. Large and medium commercial vehicles need a downtown permit in the loop from 7 to 9 a.m. and 4 to 6 p.m. on weekdays. [24]

Charlotte also requires a city permit for any vehicle over the state's size limits on city streets, and a bill of lading or delivery slip when off a truck route. [24]

Greensboro defines a truck as over 26,000 pounds or more than 2 axles and lists its routes in Schedule No. 8. Winston-Salem keeps trucks off marked streets unless they are delivering there. [25][26]

Using GPS without trusting it blindly

FMCSA says bridge-strike data suggests some drivers were using navigation meant for cars. It urges truck drivers to use a system made for trucks and buses. [27]

Its tips: enter your truck's height and other details before each trip, keep the maps updated, don't type while driving, and always obey signs about low bridges and weight limits. [28]

FMCSA's research page adds that no rule requires states or cities to document every low overpass, so a truck GPS can miss one. FMCSA's advice is to follow the signs. [29][28]

No NC law on truck GPS use turned up in our research. The practical rules are the ones above: know your height, watch for the yellow sign and follow the city's truck routes. [1][14][22]