About 13′6″

13 feet 6 inches is the standard height of a semi-trailer in the United States — and the height a bridge must clear for one to pass under it. Thousands of bridges don't. Trucks hit them constantly: railroads lose service hours, highways close, drivers are injured, and occasionally bridges are destroyed outright.

Yet there is no public national record of bridge strikes. State DOTs track them unevenly; railroads keep their numbers private; local news covers each crash as if it were the first. This site keeps the record: every documented strike, pinned to its bridge, with links to the news reports, DOT notices, and official investigations that documented it.

Where the data comes from

Incident records are compiled from public sources — news coverage, DOT press releases, NTSB reports. Each incident links to its sources. Records marked “needs review” have been compiled but not yet field-verified; bridge coordinates may be approximate.

Sources & attribution

Beyond news reporting, these datasets do real work here. Where a bridge page credits one of them, the credit belongs to the publisher below — not to us.

• City of Chicago, Department of Transportation — Viaduct Clearances, the City's list of posted clearances beneath its viaducts. Our copy is a 2017 snapshot, so treat it as historical: clearances get re-signed.
• OpenStreetMap contributors — © OpenStreetMap, available under the Open Database License (ODbL). Used for bridge coordinates, the names of the railroads carried, and maxheight tags that independently corroborate a posted clearance. OSM is never the sole source of a clearance we publish.
• FHWA — the National Bridge Inventory (2025), used for structural clearances and coordinate verification. Note that NBI generally does not cover railroad bridges over local city streets — many of the worst offenders here.
• Mapbox and Maxar — basemap and satellite imagery.

A posted sign and a measured structural clearance are different numbers, and agencies usually post below what they measured. Where two sources agree we say so; where only one exists we say that too.

What this site is not

Not a navigation aid. Clearances change, signage changes, and this record is not complete. Know your height, and trust the posted sign over anything on the internet.

History

This project began in 2011 as a crowdsourced low-clearance map for the trucking community, seeded from Federal Highway Administration bridge inventory data. It relaunched in 2026 with a different focus: the documented public record.

Contact

Spotted an error, a bridge we're missing, or have a strike to report? Email info@13-6.com. Corrections and new sightings are welcome — this is a public record, and it gets better with them.