That’s a pet peeve of mine as well. Unfortunately, I have a physical impairment that highly restricts my mobility. It may sound rather biased, but I’m one of the few people that can actually justify leaving the cart where it is. Conversely, I like how they handle this in Europe, especially Italy. Each cart has a coin slot were you put in a one euro piece in order to unlock it from the rack like airport carts. When you’re finished loading your groceries in your car, you have to take the cart back to the queue where you interlock the cart into the other carts to retrieve your euro coin. That’s the incentive and it works very well. There are absolutely no empty carts laying around in the parking lot. This also reduces theft. They handle all the grocery bags in a similar fashion. Everyone brings their own cloth bags from home or pay the price for bags as you’re checked out. They’ve been doing this for decades, and this is one thing that I think would be helpful here in the states.