This simulation is similar to the [url=http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=226]traffic light contril[/url] I have created many years ago. But I rewrited it with ejs. You can click the +/- sign to change the time delay between traffic lights.

Virtual Physics laboratory Original URL

Fu-Kwun Hwang, Dept. Of Physics, National Taiwan Normal University.