There’s a small bug that seems to be present in many traffic light controllers that allows you to deny an advance left turn to oncoming traffic.  I’ve seen a few other drivers doing this (including a transit bus) so I don’t think this is anything new.

If you see an oncoming car in the left turn lane, don’t pull up to the stop light, pull up 1.5 car lengths behind it.  You may be able to see where the sensor loop is if it hasn’t been paved over.  Once the cross-traffic clears, both sides will just get a regular green light and you won’t have to wait for the turning traffic.


This only works when:

  • That specific light is triggered by a sensor loop.  If it’s timer based, this won’t work at all.
  • The cars turning left from the cross-street didn’t cut the corner to tightly and run over the sensor.
  • There isn’t anybody in the left turn lane on your side

A word of caution however: the turning car may be expecting the advance and may not notice that they don’t have it. Try not to drive into their side as they cut you off.