In Oslo, Norway I talked with few car owners that were affected by removal of parking spaces in the city. They supported it as it saved them time. They need to walk more to the parking, but they spent less time sitting in traffic jams.

There is no single factor that contributed. Perhaps it is more efficient if everybody drives to one big parking, perhaps people overall started to use cars less, perhaps rash hour became more spread in time leading to lesser max car density and smaller jams. Whatever the reason, it was win-win.