Though they turn out to be more expensive than simple radio transmitters because of many factors. My first vision of this is there is minimal physical construction to keep things cheap. You re-paint the lanes and put up signs and a small number of transmitters. As GPSs become cheaper to put in small electronic devices, the receiver that tells you when to use the lane gets cheaper.

The receiver has the advantage that the cars pay for that end of the infrastructure, and in fact pay extra to fund the whole thing if need be. Lights that are frequent and visible are expensive. A traffic light at an intersection is $150,000 believe it or not. Government. Small radio relays on the other hand could be easily $100 in quantity because they could be placed indoors in the homes and offices along the route, mostly, or at higher cost on ordinary streetlights or along with the wifi infrastructures many cities are putting in right now.

And yes, California has that law about yielding to a bus too. BRT is beyond that — dedicated ROW and also control of the traffic signals, so the bus is doing almost as well as if it had its own subway tunnel.

This is important because let’s face it, travel by even express subway is slower than your own car because with transit you have to wait for it, it doesn’t go exactly where you’re going and you may have to change. So it needs every advantage while you’re on it, such as the timed lights.

But there’s no reason to not make use of the empty ROW behind the busses if the spacing is sufficient to allow V-Row.