Traffic Lights

I’m surprised by how many seemingly experienced cyclists really have no clue how to trigger a traffic light to make it turn green. Unfortunately cities don’t do much to make it easy for cyclists ride legally by marking the detector, but 90% of the time it is possible to ride with the flow of traffic and get a green light.

When you approach an intersection that is not occupied by a motor vehicle, be on the lookout for cutouts in the asphalt. Place your bike directly over the cutouts to increase the likelihood of being detected. I have about 98% success with this method (most intersections 100%, though if the cutouts have been paved over, 0%). Over time you get to know which ones work, and which don’t. John Allen has a great article on using these loop detectors.

If you encounter one that doesn’t work, try contacting the agency responsible for the maintenance of that particular intersection. Marked Signal Detector in Folsom.Some are very responsive (Chico, CA, Folsom, CA, Davis, CA), and others (Sacramento County, Rancho Cordova, CA) seem unconcerned. I wrote an e-mail to the city of Folsom about a detector that had been paved over. Within a day they put in a temporary marking indicating where it was, and shortly thereafter they painted a permanent standardized marking! Most cyclists are ignorant of even these markings. I sometimes wonder how oblivious people must be to not see them, but I point out this marking to other cyclists at least once per month. If you see such a marking, just park your bike over the mark and the light will eventually turn green!

OK, and while I’m preaching… 🙂 Don’t stop too close to the curb! The CA DMV website says:


  • must ride in the same direction as other traffic, not against it.
  • must ride in a straight line as near to the right curb or edge of the roadway as practical— not on the sidewalk.
  • must make left and right turns in the same way that drivers do, using the same turn lanes.
  • may legally move left to turn left, to pass a parked or moving vehicle, another bicycle, an animal, or to make a turn, avoid debris, or other hazards.
  • may choose to ride near the left curb or edge of a one-way street.
  • may use a left turn lane. If the bicyclist is traveling straight ahead, he or she should use a through traffic lane rather than ride next to the curb and block traffic making right turns.
  • are lawfully permitted to ride on certain sections of freeways, when signs are posted. Be careful when approaching or passing a bicyclist on a freeway.

Warning, bad artwork follows….
Stopping At Intersections Notice the red and green lines in this figure… if you stop where the red line is drawn you encourage motor vehicle drivers to squeeze alongside you rather than waiting for you to clear the intersection. Worse, you are also giving them implicit permission to pull along side of you, forget you are there, and then turn right in front of you! Very dangerous! Also, never stop or pass to the right of a car that is already stopped as they may suddenly decide to turn right, or a passenger may open their door to get out!

OK… done preaching! 🙂