My home course just added GPS to the carts this season. When they announced this I didn't care, since I hardly ever ride a cart.
Now I really do care! I played there for the first time this season with my dad a few days ago, and he rode in a cart as usual. On the second hole he was off to the right of the green and his cart started beeping. LOUD! He couldn't figure out why so I went over and had a look, and the GPS unit said "restricted area". I managed to drive it around the green to the next tee. I thought maybe it was beeping because the GPS signal was blocked by the trees and it became confused. Then on the 4th hole it happened again, only this time it wouldn't go forward at all once he got about 50 yards short of the green.
Turns out they are using the GPS to enforce some really big boundaries around the greens. On some holes you can't get within 80 yards of the green if you are very far off the cartpath, on a couple of the par 3s it is essentially cart path only. Thing is, my dad is 78 years old. Too much walking wears him out, and he's not a particularly fast walker these days either. It took a lot more walking on his part and of course more time due to the way the cart forces him to stay on the path starting so far from the green.
If there had been problems with people driving up right next to the greens and damaging them I could understand this, but while I have seen this once in a while from golfers who didn't know better it was pretty rare and it isn't like there were tire marks on the fringes. They are going way too far in enforcing such huge boundaries short of the greens without regard for older or disabled golfers. I could see this thing being useful on "cart path only" days, but why a par 3 that's all rough until 10 yards away from the green needs to be cart path only for its entire length every single day eludes me.
Anyone ever seen anything like this before? Maybe this is common and I just don't see it since I don't ride carts often, but this is new to me. The most annoying aspect of it is that the GPS in the carts is like something out of the 90s. Monochrome screen, with no buttons or functions AT ALL. Just tells you the distance to the front, middle and back of the green from where you are. That's it. Guess they spent all the money on this system to make my dad want to play elsewhere more often!