Except speeding isn't a crime in GTA, and it never will be.
But the option to have it on or off would suit everyone.
Everyone says that about everything. It's still a feature that takes time to develop, and adds nothing to gameplay. You never need to know how fast you're going, what gear you're in, or what rpm you're sitting at.
Well it could give the option to have speed limits on or off. It's a matter of personal choice if you want to use it or not.
Can't have too many options.