I’ve mostly seen them in parking garages so I assumed it’s for throughput.
if you back into a spot, you’re holding up everyone behind you. If an impatient driver is too close you may back into them
by fronting in, there’s essentially no wait, no risk of backing over that tailgater. When you want to back out, you wait until traffic is clear rather than block them
I’ve mostly seen them in parking garages so I assumed it’s for throughput.