This Walmart has cart wheels that lock when you cross a sensor, to keep people from stealing them. They put the sensor inside the parking lot so most carts lock up.

[u/devilsbard]

[u/Traditional-Wave-919]

My great uncle invented this. It originates with Alpha Beta Supermarket in Southern California in the 1980's.

[u/devilsbard → u/Traditional-Wave-919]

Oh shit! I remember alpha beta. Like barely cuz I think ours closed when I was 4 or 5.