On a similar note, my city used to have a lot of 50 km/h four lane streets through residential areas, even though they were only minor trunk roads that didn't warrant that many car lanes. There was also a severe dearth of bike lanes, and since these are residential areas with lots of houses, there were always cars parked in the right lane and cars turning left into driveways.
The solution was to remove two lanes of traffic, forbid street parking, add a bike lane along each side of the road, and add a centre turning lane. this was all done with just paint and "no parking" signage. There was a bit of complaining about the loss of street parking, but other than that it's worked out great, and I actually see people using the bike lanes now, and traffic actually flow smoother.
The solution was to remove two lanes of traffic, forbid street parking, add a bike lane along each side of the road, and add a centre turning lane. this was all done with just paint and "no parking" signage. There was a bit of complaining about the loss of street parking, but other than that it's worked out great, and I actually see people using the bike lanes now, and traffic actually flow smoother.