Remember Los Angeles used to have red light cameras, but the city council voted to remove them because the city lost money on them, if I recall correctly. (The contractor received millions, but many people didn't pay the tickets.) The police chief at the time (Bratton) railed against the vote, claiming (rightly) that red light cameras save lives. He was right. But nobody cared, because dealing with a red light ticket may cost near $600-$800, and for most people that's a life-changing punishment. Some cities even ticket for making an illegal right turn at a red light, at full price.

There are solutions already available to mitigate traffic. For example, the Nimbys in the neighborhood of my children's magnet school successfully got the city to close off access to the road I used to enter the neighborhood, forcing me to drive around the neighborhood to enter. (My complaints fell on deaf ears, even though one of our school buses was forced to make an "illegal" turn everyday.) They also have speed bumps on the streets leading up to the school. This is not rocket science, for Nimbys have been doing this for thousands of years.