One of the reasons surface streets (outside of the West Side) in most of Los Angeles run pretty well, even at rush hour, is that 90 percent of the traffic lights in LA are synced. By the end of the year, all lights will be synced. As a conseqeunce, despite its traffic, in most parts of LA, one needs to wait for only one light cycle to get through an intersection. Again, this is usually even true on downtown streets during rush hour.
The cost of syncing all the lights in Los Angeles will come to $350,000,000. Let's do a back-of-the-envelope here. If syncing saves the average Angelino (there are 4 million) even one minute per day, and time is worth $15 per hour, syncing basically pays for itself within a year. That is government spending everyone should be happy supporting.