The FastTrak in the SF Bay area lets you go through at about 20 at booths and at a new bridge, there isn't any structure across part of it and FastTrak users can go 40. The Oakland-Bay Bridge (the one that had part collapse back in 1989 and the replacement is currently being constructed) has 15 toll lanes which narrow down to 5 lanes on the bridge. They have metering lights to control the chaos, but they go on at 6:30 AM or so and the traffic can back up at least a half mile or so.
Then the traffic has to slow down on the bridge to 35 because thare is an "S-curve" , put in last year where the new bridge will connect to the tunnels through Yerba Buena Island. There have been many accidents there. A semi went over the side one night. They have rumble strips, dots on the road, large signs with flashing numbers and cops sitting there and still the accidents happen.