For years, I worked in a large building that required all employees and visitors to back in for a few safety reasons, with approximately 600 spaces and an almost full lot most weekdays. It was stated in our safety training that it was easier to see other people and vehicles when exiting facing forward and faster evacuation in times of extreme emergency. It had the benefit that it did seem to quicken flow of traffic when everyone left around the same time at the end of the day.

If a parking spot is straight, I tend to back in for those reasons, but if it is an angled spot, it typically denotes a singular directional flow, and it makes more sense to pull in and back out.

The only issue with pulling-through in a parking lot is one-way lanes with angled spots (the majority of parking lots in my area) because then you’re pulling forward against the flow of traffic or have to make an extremely sharp turn upon exiting. It’d be fine with straight spots or two-way lanes, but people still do it in the former circumstance and end up driving the wrong way.

All is fair in love and war… Or something like that