This is one of the proposals we had made for 2nd Ave in NYC awhile back. There are 2 problems though: 1. People would have to cross the bus lane to access parked cars. I think it's doable at a relatively low bus volume but cities might feel otherwise. 2. You still face conflicts between the bus and turning vehicles. If the turning vehicles could be kept out of the bus lane, you would have to signalize the turns and stop the buses. The best way to deal with this 2nd problem would be to put the parking-protected bus lane on the left side of a one-way street and prohibit left turns (it is easier than banning right turns). You would then need to build bus boarding islands between the bus lane and the moving traffic lane.