Backward spikes

On my way to cross the international border the other day, I drove near the Duty Free shop. It's where you can purchase items a little cheaper. You are supposed to go in, buy your stuff and exit out the other side to cross the border. Coming back the way you entered isn't possible because they have backward spikes there.

As I drove up I noticed a car just past the entrance facing the wrong way. All 4 of his tires were flat and he was on his phone calling for help.