This is really unprecedented. Caltrans is implementing traffic calming on the Bay Bridge “S-curve” to control speeding.
Caltrans, working together with the CHP has decided to slow traffic down across the new S-curve on the Bay Bridge, by closing one to two lanes of the Bay Bridge’s upper and lower decks during off-peak hours.
Traffic engineering practice in the US is to build roadways wide enough to accommodate peak-hour LOS (level-of-service). The result is that during off-peak hours (which is much of the day in many locations), highways are grossly overbuilt, leading to speeding and dangerous passing.
A relatively simple safety solution is to close off superfluous lanes during off-peak hours, so as to moderate speeds and reduce accidents. This also provides much safer environment for cyclists and pedestrians.
If it can work on the Bay Bridge, it can work anywhere.