I live in Scotland, have two former racing greyhounds, and I'm very grateful for a local farmer who has a dog run / playpark with an honesty box we can drop something in to help with upkeep when we give our two a nice run.
We don't have leash laws like in the US, so it is common for dogs to just be allowed to run around in most community parks.
The problem with sighthounds is they will lock on to squirrels, rabbits or other things, and running at 40mph will be out of sight and lost VERY quickly.
So we don't let ours off lead except in controlled places (like this one).