Crash on Overseas Highway in Key Largo snarls northbound traffic, delays

A motor vehicle crash on the northbound Overseas Highway in Key Largo turned one of Monroe County’s most important roads into a bottleneck, backing up U.S. 1 at Mile Marker 104 and sending delays through the Upper Keys.

The crash was reported at 11:45 a.m. on April 19, 2026, and first responders were on scene as drivers were told to use caution and expect delays. The location, northbound Overseas Highway at Mile Marker 104, sits in one of the busiest stretches of the Florida Keys travel corridor, where even a single lane problem can quickly slow traffic for everyone from local commuters to delivery trucks and tourists.

In Monroe County, there is essentially one main highway in and out of the island chain, which means a crash that might be minor on a mainland street grid can have a much wider effect here. A blocked or slowed stretch of U.S. 1 can ripple into school pickup times, business deliveries, emergency response routes and the steady flow of traffic moving between Key Largo and the rest of the Upper Keys.

The incident did not include immediate details on injuries, vehicles involved or how many people were at the scene, but the disruption was serious enough to warrant a breaking-style traffic alert. That kind of notice usually means responders were managing lane blockage, cleanup or traffic control while northbound drivers crept past the scene or waited for the roadway to clear.

Florida Highway Patrol says its live crash and road condition reports are updated every five minutes, but incidents inside city limits may not appear on the map if FHP is not handling them. The agency also says live crash information is not archived for later statistical review, which makes real-time alerts the most useful tool when a crash snarls the Keys.

The Monroe County Sheriff’s Office keeps a public active-calls feed updated regularly and links motorists to Florida Department of Transportation and Florida Highway Patrol traffic resources. In a county where the Overseas Highway is the lifeline for nearly every trip, a crash at Mile Marker 104 is never just a local fender-bender. It is a reminder of how fragile the corridor can be when one collision slows the only major route through the Florida Keys.