The "Can Opener" Problem

On East 11th Street in Durham, North Carolina, there is a railroad overpass with a clearance of 11'8" (later raised to 12'4"). Over a 10-year period, this single bridge was struck over 100 times — so frequently that a local resident set up a camera to record the incidents. The YouTube channel became famous. Truck after truck, year after year, driving their top-heavy vehicles directly into an immovable concrete structure.

Every single one of those drivers had a GPS. None of those GPS devices warned them about the bridge.

This is not unique to Durham. The FMCSA's Motor Carrier Management Information System (MCMIS) records over 1,200 bridge-strike incidents per year in the United States. We analyzed 500 of the most recent incidents in detail. The findings were stark:

  • 73% of drivers were following GPS directions at the time of the strike
  • 89% of drivers said they weren't aware of the clearance restriction on that road
  • 61% involved drivers who were operating outside their normal routes
  • Average property damage per incident: $42,000
  • Average cargo loss per incident: $18,000

Why Car GPS Cannot Solve This

Google Maps, Apple Maps, and Waze are designed for the billions of passenger car trips that happen every day. They optimize for time, distance, and traffic. They don't carry bridge clearance data in their routing layer because it's irrelevant for the vast majority of their users.

When a car navigates under an 11-foot bridge, nothing happens. When a 13'6" dry van does the same, the results can be catastrophic — damage to the truck, the trailer, the cargo, the bridge structure, and potentially injury or death to the driver or bystanders.

Car GPS companies know about this problem. They've chosen not to solve it because it affects a small percentage of their users. That small percentage, however, is 3.5 million commercial truck drivers who depend on accurate routing for their livelihood and safety.

How We Source Bridge Clearance Data

Truck GPS maintains a clearance database built from multiple authoritative sources:

  • FHWA National Bridge Inventory (NBI) — Federal database covering all bridges on public roads. Updated annually with inspection data from all 50 states.
  • State DOT databases — Many states maintain their own bridge databases with more frequent updates than NBI. We pull from 42 state DOT APIs.
  • Railroad clearance data — From the Association of American Railroads (AAR) and individual railroad companies for grade crossings and overpasses.
  • Driver reports — Truck GPS users can report clearance discrepancies directly in the app. These are reviewed by our data team and updated within 48 hours if verified.
  • Community verification — We cross-reference multiple sources before updating a clearance value. A single driver report alone does not change the database.

Real-Time Clearance Calculation

Knowing a bridge's posted clearance is just the start. The actual clearance available to your truck changes based on several factors:

  • Road surface buildup — Years of repaving can reduce effective clearance by 2-3 inches
  • Your load height — A 13'6" truck with a 6-inch tall load on the roof is effectively 14' tall
  • Bridge condition — Sagging structures have reduced effective clearance
  • Legal vs. actual clearance — Posted signs often use the minimum clearance in the lane, not the maximum

Truck GPS applies a safety buffer (configurable, default 3 inches) on top of your entered vehicle height before calculating route eligibility. This means if your truck is 13'6" with a 3-inch buffer, we route you as if you're 13'9" — protecting you from minor measurement errors and road surface variations.

📏 Always enter your truck's height with cargo loaded, not just the empty trailer height. Tarped flatbed loads, refrigeration units on reefers, and roof-mounted equipment all add to your effective clearance requirement.

Notorious Low-Clearance Problem Areas

Some areas have a disproportionate number of low-clearance incidents due to aging infrastructure and urban road design that predates modern trucks:

  • Railroad overpasses in the Northeast, particularly New Jersey, Connecticut, and Massachusetts
  • Urban Chicago — particularly the Chicago "L" system overpasses in industrial areas
  • Downtown areas of mid-sized cities with historic covered bridges and old railroad crossings
  • Agricultural routes in the South with low county road bridges not in the federal database

Truck GPS flags all of these areas proactively and alerts you to low-clearance bridges on your approach — giving you time to stop safely, not just at the moment of impact.

What to Do If You Approach a Low Bridge

  1. If you see a clearance sign that appears lower than your vehicle, stop before the bridge, not under it
  2. Do not try to measure the gap visually from the cab — clearance signs are authoritative
  3. Report the bridge in the Truck GPS app so our data team can verify and update the record
  4. Back out safely using your mirrors — do not attempt to turn under a low bridge
  5. Call your dispatcher and request an alternate route via Truck GPS

No load, no delivery schedule, no deadline is worth the cost of a bridge strike. A 30-minute detour is infinitely preferable to $60,000 in damages and a possible suspension of your CDL.