I think he is referring to incorrect map data, which would be much more dangerous than missing map data.<p>Leaving aside malicious map data for now, high-speed roadways would tend to be well mapped, and low speed roadways should be discoverable in real time.<p>What could be very dangerous is bad map data in addition to a construction zone or road washout. I do think that places like construction zones will be the first to have V2I (vehicle to infrastructure) installed - to be extra sure that vehicles are aware of unusual conditions.