Signs about carts stopping at the YELLOW LINE at Wal-Mart?

Question

How do these signs work and what does these signs warn you about?

It says something similiar:

Carts will automatically stop at yelllow line and will not go any further.

What is the purpose of these?

Answer 1

My Wal-Mart does not have these. If they at the cash registers it would provide air space and privacy for the customer ahead of you. If they're at the doors it keeps patrons from removing the carts from the store. Maybe some additional info will get you some better answers.

The Muse

Answer 2

It isn't just Wal Mart.  Many cities have a growing problem with bozos thinking they are entitled to take the carts home just because they buy a few groceries.  These carts are very expensive.  It's bad enough that stores have to pay a service to cruise the city picking up carts.  It is worse that kids throw them in rivers, and ditches.   I had a neighbour that used to take a cart home every week, and when she would have a dozen or so in her back yard, call for pick-up.  That ended when the police knocked on her door.  

A system has been developed that has auto locks on cart wheels, and a sensor grid around the perimeter.  If the cart is removed from the property, brakes lock the wheels solid.

Answer 3

It is for stopping thief, those carts cost about $500.00 each.

Answer 4

It's so people don't steal the carts.

It has a sensor, so once you pass the yellow line the wheels lock.

Answer 5

Carts automatically stop at the yellow line.  That's pretty clear.

There are people who would take the cart home if they could. Carts are expensive.  Stores don't want them stollen, so they put a sensor in them that won't go past the yellow line in the lot.