As an example: More and more "cars are guests" roads are being added. These are usually cycling dominant routes and while completely removing cars might be preferable it's not always possible. Due to the roads being designed as widened cycling paths (and look like it) which barely fit a car you can have cars there but you'd think twice driving there, which makes the drivers more cautious and lowers the car traffic volume a lot. Note: the throughput of a cycling path far exceeds that of a normal road per surface area used (about ab order of magnitude vs cars).