(In the UK)
We've recently moved to a house with an extensive gravel driveway (probably getting on for 2500m2). Being springtime the weeds are just starting to pop their heads out. Our current tactic is simply to pick them out by hand each time we walk down the drive, spending maybe 30 minutes between us on it per day.
Is there a better solution? Obviously I know that weedkillers exist, but then you're just left with dead weeds, which presumably breakdown in the gravel and serve as extra organic matter to feed... new weeds?!
The gravel does have weed-control fabric under it, but most of what we're picking out at the moment is just rooted in the gravel itself. They do come up easily at least!
Hopefully it's not too long before someone makes a gravel weed-lopping Roomba...