Bike lanes that end abruptly and dump cyclists into high-speed traffic have no federal design standard requiring safe merge transitions

Across the United States, bike lanes simply end. A painted lane runs for eight blocks, then stops at a sign that reads "Bike Lane Ends" or "Share the Road" — and the cyclist is suddenly in a 35-40 mph travel lane with no transition, no merge zone, and no warning to motorists that a cyclist will be entering their lane. In Washington DC, the bike lane on New Jersey Avenue ends abruptly, forcing cyclists to ride unprotected through Capitol South before reconnecting with bike infrastructure at Independence Avenue. This pattern repeats in every American city: bike lanes are built in segments where right-of-way is available, with no requirement that they connect to each other. The danger is not hypothetical. When a cyclist merges from a protected or semi-protected facility into a general travel lane, they are making a lane change into faster traffic while being the smallest, slowest, least-visible vehicle on the road. Drivers in the travel lane are not expecting a cyclist to appear from the right because, for the preceding blocks, cyclists have been separated from them. The speed differential at the merge point is typically 15-25 mph, and the cyclist has no acceleration capability to match traffic speed. This is the inverse of a highway on-ramp: instead of an acceleration lane that lets you match speed before merging, the cyclist gets a painted line that evaporates. The problem persists because there is no federal standard requiring safe termination treatments for bike lanes. The MUTCD (Manual on Uniform Traffic Control Devices) provides guidance on bike lane markings but does not mandate specific merge transition designs. Cities build bike lanes project by project, each project ending at its funded boundary, with no requirement to connect to the next segment. The result is a network of disconnected fragments — what advocates call "bike lanes to nowhere" — where the most dangerous moments of a ride are exactly the points where the infrastructure abandons you.