Google Inc. threw the auto industry another curve ball Wednesday, saying its autonomous cars should be on public roads within five years without having to drive through a thicket of regulatory red tape.

Speaking at a conference in Detroit, the chief of the software giant’s autonomous-car project, Chris Urmson, indicated widespread auto industry concern about regulation of self-driving cars is overblown. The onus, he said, is on developers of these vehicles to tackle safety challenges and work to boost public acceptance.

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