Maple Grove researcher tests app for visually impaired

Chen-Fu Liao says a simple tap of a touch screen can guide visually impaired walkers across the street. 

Liao is a researcher at the University of Minnesota and the Center for Transportation Studies. He developed a smart phone app designed to go beyond existing crosswalk aides.

Some intersections have what’s called an APS, or Accessible Pedestrian Signal. At the press of a button, a voice tells pedestrians which street they are crossing, when it is safe to cross and how much time they have to get across the street. Liao says some people complain the buttons are hard to find and the audio is hard to hear.

"We decided maybe we can provide a signal information to the visually impaired through the smart phone since a lot of people are using their mobile phone right now," says Liao, "It’s more a personal device, personal solution."

His cell phone app is designed to not only request a walk signal and give visually impaired walkers a countdown to cross, but also to give them a layout of the intersection.

Friday, Liao rigged the traffic lights at the intersection of Highway 55 and Rhode Island Avenue in Golden Valley to test his system.

To demonstrate how it works, he points a smart phone equipped with the system to Rhode Island Avenue. With one tap of the touch screen, a voice says through the phone’s speaker, "You are pointing east. Rhode Island Avenue. Four lanes."

"When I do a double tap, it sends a request to the controller to request for pedestrian crossing," says Liao. "And every eight to 10 seconds, also, it updates the status to wait for a walk signal."

Several volunteers came out to the intersection to test the system. Sue Jasmine is one of them. She is completely blind.

"It’s common for people to get hit. And now that cars are getting even quieter, especially if the drivers aren't paying attention, it's going to be more and more common that it’ll be harder to hear the cars," says Jasmine. "We deserve the same ability to gauge the traffic lights as everybody."

Liao says Friday's testing is shedding light on some issues. Jasmine and other volunteers complained the audio is difficult to hear over loud traffic. But they’re encouraged with the possibility of such a system one day being implemented.

It took Liao two years to develop this crosswalk app, to the tune of about $200,000. The project is funded by the U.S. Department of Transportation.

Liao's next step is to work with public agencies, cities and the Minnesota Department of Transportation to see how to implement this widely. He will use data collected from Friday’s test-run in these discussions.

Liao says it will likely be years before we see his system widespread throughout the Twin Cities. His ultimate goal is to develop an app that gives the visually impaired turn by turn directions using his crosswalk system as a main component.

Renee Banot

April 20, 2012


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