For a standard GPS head unit, the burden of proof that a road exists and is appropriate to drive on may be some purchased telematics database, itself combined f

For a standard GPS head unit, the burden of proof that a road exists and is appropriate to drive on may be some purchased telematics database, itself combined from all kinds of different sources. The burden of proof for a Google self-driving car is that the road recently had every feature (curb, sign, mailbox, lane marking, etc) mapped by a Google employee.