There are three categories of runway incursion types: operator/ATC error, pilot error, pedestrian/vehicle. Even if someone 'knows' that they need to "hold short runway 12", they can still have a brain fart and go through the hold short line.
Unless you want to argue that all vehicles taxiing have to operate (SAE Level 4) autonomously?
Yes, I know it probably costs $300k, surely today you can have a $10k ground version.
You could also show every plane on a screen inside the vehicle and have some loud alarms if they are on a collision path.
You could even just display FlightRadar24, still better than nothing.
You would still get permission for the tower, this would not be an allow system, just a deny system.