At some intersections, cars will stack twenty back on all lanes before the light gives them right of way. The logistics of moving them aside would take longer than just waiting for it to change.

This proposal is to add systems which change the light when an emergency vehicle approaches, so the issue never had to come up in the first place.

Edit: Also there needs to be space to the side to move the car. Doesn't matter how much space you leave in front for turning if all ways are obstructed.