They turned the corner, coming upon a rare sight. It was a motor vehicle accident, first in the business district for months. A school bus lay on its side, just short of the intersection. Children were clambering cautiously from the emergency door. The uniformed driver was ignoring his passengers, staring in disbelief at the radar controls at the street corner, which had failed a moment earlier. The other vehicle involved in the crash was wrapped around a power pole. It was an auto of antique vintage, produced before full automatic driving provisions. There weren't more than a dozen such vehicles remaining on the streets of the city. The radar controls almost never went on the blink. Only the combination of the vehicle and the inoperative controls could have created an accid............