Mahan, who is blind, had the chance to sit in the driver's seat when he and a licensed driver took a ride in one of the vehicles nearly four years ago, but his dream of being able to have more mobility is one step closer to becoming a reality after a federal ruling re-defined what can be classified as a driver.
U.S. officials will now allow the artificial intelligence system responsible for piloting self-driving cars to be considered the driver, according to a letter dated from last week from the National Highway Traffic Safety Administration.
The Feb. 4 response from NHTSA gives Google and all other manufacturers approval to design and operate under the interpretation that their artificial intelligence systems qualify as the driver under federal law.
It's something that could radically change everyday life for Mahan, who lives two miles from the nearest bus stop and relies on the VTA Paratransit Service when his family members are at work.
"It's like riding with a fabulous driver," Mahan told ABC News owned station KGO-TV about his ride. "Anybody who spends five minutes out in that traffic will realize that the danger [is] the humans. Personally I can't wait for the robots to start driving."
ABC News' Jeffrey Cook contributed to this report.