Other than property rights issues, sometimes there is a FAR zoning issue , or insurance issues.
What if someone slips on some ice and gets hurt. Does your insurance cover your land that has their driveway which is not properly maintained ?
I’m sure my insurance company doesn’t have a clue about the property line/driveway issue. And given that I only own half of it and a third property owner is the only other legally authorized user of the driveway, anybody trying to figure out who to sue would be in quite a muddle. I mean, who is required to keep it safe? Clearly not just one party. All three parties? Maybe two parties (but which two)? I have a law degree, and recognize that it’s a bizarre situation that defies any clear legal solution in the event of a liability suit.
The driveway is not unsafe at this point (apart from occasional transient snow/ice issues), but is reaching the point where it’s obvious need of re-paving, and obvious land-settling under one side would certainly be a drag on my property value if I wanted to sell. If it develops a pothole (a fairly imminent possibility) it could start posing some risk of damage to the underside of low-slung vehicles.