OCALA, Fla. (AP) — In 2012, Steve Mahan, who is blind, climbed into the driver's seat of a self-driving car and rolled up to the drive-thru of a Taco Bell in a video that's been viewed more than 8 million times online.

The piece, produced by Google, captured the potential of autonomous-car technology to change the lives of the visually impaired.

"It was my first time behind the steering wheel in seven years and was absolutely amazing," Mahan said.

Self-driving-car advocates say that in addition to helping the disabled, the vehicles will allow people to do other tasks while driving and make roadways safer by removing human error.

But six years after Google's viral video, national advocates for the estimated 1.3 million legally blind people in the U.S. are worried the industry is not factoring their needs into the design of the new technology, a mistake they say will make the cars more expensive and harder for them to access.

"Although we have been held up as obvious beneficiaries of the technology in conversations and presentations, this will have just been exploitation if the systems are not accessible," said Anil Lewis, executive director of the National Federation of the Blind's Jernigan Institute.

"How about instead of Taco Bell, we demonstrate a blind person independently operating an autonomous vehicle, dropping off his/her kids at school on the way to work, and maybe stopping by a Starbucks on the way?"

The concerns are fueling new research outside the auto industry to develop data and software meant to help ensure the needs of the blind are met when autonomous cars become commonplace.

In a University of Florida study, blind people are using experimental software that could be easily installed in cars and peoples' phones.