While planning for a 16th Street bus lane continues, DDOT has quietly made another important but nearly invisible improvement there: The traffic signals are now optimized for buses.

16th and U queue jump signal. Photo by the author.

33 traffic signals along 16th Street now have Transit Signal Priority, or TSP. TSP holds a green light a few seconds longer, or switches a red to green a few seconds sooner, if a bus is ready to pass through.

Stopping at fewer red lights speeds buses along a line. In particular, DC is using TSP on 16th Street to keep S9 buses on schedule. When one falls behind, the signal priority kicks in so that bus can catch up.

16th Street has so many buses that DDOT can’t give each one priority all the time, or it would gum up every perpendicular street along the line. But keeping buses on schedule is a nice improvement for riders.

16th & U queue jumper

In addition to TSP, at 16th and U there’s now a dedicated signal just for buses, called a queue jumper. It gives buses their own “go” signal a few seconds before cars get their green, allowing buses to jump ahead of a line of waiting cars. By the time cars get their green and start moving forward, the bus is in front of them rather than behind.

The bus signal looks different than a normal light, so car drivers don’t mistake it for one they’re supposed to follow. A horizontal bar means stop, and a vertical bar mean go. It’s the same as the dedicated streetcar signal at 3rd and H, and the same as bus signals along the Crystal City Potomac Yard transitway.

Traffic lights may not be as exciting as bus lanes, but these details matter. Thanks DDOT for making this progress.

 Comment on this at the version cross-posted to Greater Greater Washington.