Duplex driveway question

[Kirk B]

If you have a duplex property with a driveway that is only 1 car length wide, how do you handle parking? I can forsee major issues should one tenant be blocked in with the other tenants vehicle behind them.

I could potentially turn the small backyard into a parking lot, or limit parking to only one tenant who would pay slightly more rent.

Suggestions and experience? Seems like it could be a common issue many have had.