How do stoplights detect a car?

cainer on October 22, 2009, 11:20 pm

a magnetic sensing loop, there is one aproximately 1/4 mile from the signal

mds2004 on October 23, 2009, 1:00 am

The correct answer is.....some are weight, but the vast majority thesedays are magnetic.

gizmotron on October 23, 2009, 1:00 am