A system for monitoring shopping carts or other human-propelled carts includes wireless access points that communicate on a wireless network with wheel assemblies of the carts. The system is capable of monitoring a path followed by a cart in a store or building, and using the path (optionally together with other criteria) to determine whether to authorize the cart to exit. For example, if a shopping cart fails to pass through a checkout lane of a store, the system may perform an action that blocks or inhibits the shipping cart from exiting the store.