How are the yellow and all-red clearance times calculated for a traffic signal?

Yellow time is calculated using a nationwide standardized equation based on the speed of traffic on the roadway. The majority of Coppell’s major roadways have speed limits around 40 miles per hour; consequently, a yellow time of about 4 seconds is used at most traffic signals.

The all-red time is also calculated using a nationwide standardized equation for a given speed. The City of Coppell uses all-red values that range between 1 and 3 seconds, depending on the intersection width and speed.

Show All Answers

1. Who do I contact to report a problem with a traffic signal?
2. Who maintains all of the major traffic signals on the outskirts of Coppell?
3. Does the City of Coppell record any of the video from its traffic cameras?
4. How are the yellow and all-red clearance times calculated for a traffic signal?
5. How do you decide where and when to install traffic signals?
6. How do I request a new traffic signal?
7. Who do I contact to report a malfunctioning school zone warning flasher?
8. Can speed bumps/humps be installed on my residential street?
9. Can parking be prohibited on my residential street?
10. What can be done about speeding on my residential street?
11. Can an intersection be changed to allow 2 lanes to turn right?
12. Who maintains all of the signs in the City of Coppell?
13. Can a “Children at Play” sign be installed in our neighborhood?
14. Can a Stop sign be installed on my residential street?
15. Who maintains the pavement markings in the City?
16. What does "Stop Here on Red" mean?