parking garage arrive at a much slower, more spaced out timing which allows for backing in delays in the parking garage. Then when the people leave after the event, bring the cars back out is much faster which is a bonus for the owners picking them up; I think that is where the safety comes in; not from the way the car is parked physically at all.

I will tell you, it is annoying sitting waiting for the car in front of me at church who is repeatedly trying to back-in park but has to re-adjust their car 3-5 times because they can't backup straight - which makes the 4-5 cars waiting to enter and get past the person really love their neighbor.