This Silicon Valley car tech firm is bringing secret weapon to the streets of Sacramento

A California startup, Phantom Auto, is introducing driverless vehicles to San Francisco, San Jose, Sacramento and Mountain View, Calif. The drivers of these vehicles operate them remotely from Phantom's office in Mountain View, sometimes more than 100 miles away. The concept would assist autonomous vehicles in situations where the autonomous technology might struggle to navigate, such as road construction. (Karl Nielsen/Phantom Auto/TNS)

SACRAMENTO, California: A Silicon Valley tech company recently posted a video front and centre on its website that may startle some Sacramentans. 

It shows a sleek black car driving across the Tower Bridge ... with no one in it.