PE.com - Commuting Blog

Fun with ramp meters

The ramp meter you encounter when you try to get on the freeway during busy traffic periods typically gives you two choices that we're all able to negotiate pretty easily.

Green means go.
Red means stop and wait for green.

But what about when the ramp meter light is yellow? I raise this because one of my colleagues, environmental reporter/blogger Jennifer Bowles, ran into this situation this morning while getting on the 91 freeway at Madison Street. Maybe this is a common thing witnessed daily by commuters who spend a lot of time on the freeway, but it was a new one on me.

The good folks at Caltrans say the yellow light situation typically results when the ramp meter is, well, ramping up. The meters activate through a combination of timing and traffic flow, meaning they are set to come on during the typical commute hours and may come on at other times if traffic counts on the freeway itself are unusually high.

The meters often start on yellow for a short period of time before they are ready to begin the work of moderating the pace at which a lot of vehicles enter freeway traffic. Once the warm-up period is complete, the ramp meter will then start cycling through with red/green/red.

Perhaps now is a good time to remind everyone that a yellow light typically requires the driver to slow down and prepare to stop. Once you have done that, if the ramp light remains on yellow, proceed with caution onto the freeway, since the light has not changed to red. Of course, once the warm-up period is over and the red/green cycle kicks in, follow it.