One reason highway traffic is so bad in some parts of the country, and the world for that matter, is because there aren't any good choices for mass-transit. If consumers don't have any good reason to choose riding a bus over taking a car, history has shown that they're just not gonna do it. America is certainly a land of the automobile, and personal use is still king. But, we are also a land that just loves us some technology. So, maybe by cramming more tech into our mass-transit options will get people to ride them. The fact that the automation of the buses in San Diego would allow more people to be crammed into a smaller lane would mean that congestion would go down, and the buses would not be interfering with other traffic. Think of the buses as a train, except the train is not bound to specific tracks. When the buses get to their desired exit, the driver takes control back from the computer brain and the rest of the stops would take place.
So, using adaptive cruise control and lane sensors, San Diego hopes to reduce congestion and speed up the morning commute. Sounds like a good idea to us!