Disciples of self-driving vehicles promise a revolution that will reduce emissions, boost productivity, revive U.S. manufacturing, and reduce deaths from traffic accidents.

Yet many enthusiasts downplay another possible consequence: The elimination of millions of blue-collar jobs so far shielded from the off-shoring and automation that decimated millions of U.S. manufacturing jobs.

Truck driver is the most common occupation in Indiana and 28 other states, according to a