For people bound to a wheelchair, the daily trip to the local store can turn into an obstacle course. But a new navigation system designed and tested in Münster, Germany, may provide some guidance in plotting the route.
City streets are full of hidden obstacles for wheelchair users
Thomas Walbaum has just been to an afternoon performance at Münster’s civic theater. Now he wants to visit the city’s main tourist attraction, the cathedral. He doesn’t know the way, so he takes the shortest route shown on the town map. But it’s a journey into the unknown – he never knows when he’ll come across an unexpected obstacle.
Just a few meters short of his goal, Walbaum comes to a halt. An imposing flight of steps to the cathedral square was not indicated on the map.
Thomas Walbaum is wheelchair bound. What is a normal task for most people in Germany, becomes a difficult, if not impossible, hindrance for Walbaum and many like him.
Thousands of German wheelchair users encounter impossible physical barriers every day in cities throughout the country. From steps to uneven roads, high curbs and narrow entry ways, very few of Germany’s streets are suited for wheelchairs.
And because they can’t really be certain what the terrain is like, most wheelchair users stick to familiar routes in their hometown or rely on friends and family to guide them through the obstacle-ridden cityscape.
Carsten Dewey, a student in computer science, recognized the problem and decided to use his skills to help make German cities a little more wheelchair accessible. He has developed a computer program for "physically challenged road users", a type of navigational system for getting around common urban barriers.
Like the more common global positioning systems (gps) found in cars, Dewey’s program is designed to help users find the best and quickest route to a specific destination.
Navigating through cities
The development of the system took Dewey, who is a landscape ecologist and computer expert, six months to complete. First, he measured several routes in the center of Münster, the project’s pilot city, and made detailed records of inclines, steps and curb heights. Then he fed the data into a computer program which analyzes the information and determines the best path from different points based on given parameters like the type of wheelchair and the physical strength and capabilities of the user.
"With navigation systems for the physically challenged, we need to pay special attention to the fact that we can’t speak of the typical wheelchair user", Dewey explained to DW-TV. Every wheelchair is different and every wheelchair user has individual requirements. "With an electric wheelchair, it might be possible to go up a slope with a 12 percent incline, but an older person in a hand-powered wheelchair wouldn’t manage this. On the other hand, an electric wheelchair is wider than a folding one, so it can’t go through gaps manageable for an ordinary wheelchair", Dewey said.
But there’s more to programming a navigation system than just knowing about the ins and outs of different types of wheelchairs. The programmer has to be well versed in the city geography. And this is where Dewey’s expertise as a landscape ecologist comes into play.
The programmer needs to take into account not only basic measurements in height and distance, but also the discrepancies in terrain. A street, for instance, could have two different curb heights depending on which side one’s standing on. So both sides need to be measured individually, and if there’s a pothole or grate at some point along a curb, this too needs to be recorded.
There’s an enormous quantity of data involved in putting together a navigation system. But the real problem, Dewey said, is collecting the data. "You have to go out and walk every individual route, check where there are barriers and obstacles and record them. That requires manpower and money," he stressed emphatically.
Thomas Walbaum is one of the program's first test pilots. For him, there’s not much high-tech involved in the program, all he needs is a computer. He loads up the navigation program onto his pc and enters in his personal data such as the width of his wheelchair and the maximum height of a curb he can manage.
Walburn’s computer then presents a list of possible routes for getting from one place to the next. Based on the computer’s analysis of the distance, the difficulty of street crossings, and any information on obstacles along the way, Walburn can decide which route he wants to take through the city.
Armed with a print-out (the system isn’t mobile yet), Dewey and Walbaum set off to test the program’s proposed route from the theater to the cathedral. Walbaum compares the recommended route with the data he entered and checks whether the computer’s description of all obstacles is really accurate enough for him.
Initially Walbaum encounters an uphill incline. But it’s not a problem, because the slope is under six percent and only 85 meters long. Walbaum has indicated to the computer that he can handle such a gradient. Then the two encounter a few steps. But this, too, is not a hindrance, as a wheelchair ramp is close by.
Green light for accessibility
After several detours along a much more indirect route than ordinary pedestrians would take, Dewey and Walbaum finally arrive at the cathedral, their destination point. Both are satisfied that the journey was well worth it. Walbaum was able to wheel his way the entire distance without encountering obstacles. And Dewey saw how successful his program was.
"I think it’s a useful invention," Walbaum told Dewey and DW-TV. "It will encourage the physically challenged to go out more often."
And this is exactly what the inventor’s program is all about. In the future, the navigation system will be integrated into mobile phones or hand-held computers. The user’s position will be pinpointed by satellite systems like GPS, and because wheelchair users need both hands, route instructions will be spoken.