Observing that, a police officer in Mountain View, California, pulled over one of the autonomous vehicles not far away from the Google campus for being too pokey. According to the Mountain View Police Department, "the officer stopped the car and made contact with the operator to learn more about how the car was choosing speeds along certain roadways and to educate the operators about impeding traffic."
In a post on Google Plus, the driverless-car team poked fun at the incident: "Driving too slowly? But humans don't get pulled over for that too often."
The post goes on to say that engineers at Google have capped the speed of their prototype driverless cars at 25 mph for safety purposes (the reasoning behind this is very likely to be the same as the city's rationale for lowering the speed limit in Manhattan last year).
Because the technology behind Google's driverless cars is still experimental, they are registered in the same class as golf carts and allowed to go as slowly as they want on public roads. The car was let go with a stern, mildly confused warning and allowed to drive itself home.
See more of self-driving cars:
Self-driving cars -- Google, Tesla
Google self-driving car pulled over for driving too slowly
Brazil's President Dilma Rousseff (L) takes a ride in a self-driving car at Google headquarters in Mountain View, California on Wednesday, July 01, 2015.AFP PHOTO/JOSH EDELSON (Photo credit should read Josh Edelson/AFP/Getty Images)
An Autopilot self-driving sign sits on the window of a Tesla Motors Inc. electric automobile store in Munich, Germany, on Monday, March 30, 2015. Chief Executive Officer Elon Musk wants to transform Tesla into more of a mass-market automaker by building a battery-cell factory big enough to supply 500,000 vehicles by 2020. Photographer: Krisztian Bocsi/Bloomberg via Getty Images
A Tesla Motors Inc. Model S electric automobile fitted with Robert Bosch GmbH automated driving technology drives on a test track in Boxberg, Germany, on Tuesday, May 19, 2015. The market for automated-driving systems might total $42 billion by 2025, Boston Consulting Group estimated in January. Photographer: Krisztian Bocsi/Bloomberg via Getty Images
A GPS driving sensor antennae sits on the back of a Tesla Motors Inc. Model S electric automobile at the Robert Bosch GmbH driverless technology press event in Boxberg, Germany, on Tuesday, May 19, 2015. The market for automated-driving systems might total $42 billion by 2025, Boston Consulting Group estimated in January. Photographer: Krisztian Bocsi/Bloomberg via Getty Images
MOUNTAIN VIEW, CA - FEBRUARY 02: U.S. Transportation Secretary Anthony Foxx inspects a Google self-driving car at the Google headquarters on February 2, 2015 in Mountain View, California. U.S. Transportation Secretary Anthony Foxx joined Google Chairman Eric Schmidt for a fireside chat where he unveiled Beyond Traffic, a new analysis from the U.S. Department of Transportation that anticipates the trends and choices facing our transportation system over the next three decades. (Photo by Justin Sullivan/Getty Images)
A camera peers out from the front grill of Google's self-driving car in Mountain View, California, on May 13, 2014. A white Lexus cruised along a road near the Google campus, braking for pedestrians and scooting over in its lane to give bicyclists ample space. AFP PHOTO/Glenn CHAPMAN (Photo credit should read GLENN CHAPMAN/AFP/Getty Images)
MOUNTAIN VIEW, CA - SEPTEMBER 25: People look at camera on top of a Google self-driving car at the Google headquarters on September 25, 2012 in Mountain View, California. California Gov. Jerry Brown signed State Senate Bill 1298 that allows driverless cars to operate on public roads for testing purposes. The bill also calls for the Department of Motor Vehicles to adopt regulations that govern licensing, bonding, testing and operation of the driverless vehicles before January 2015. (Photo by Justin Sullivan/Getty Images)