Bike sharing is increasingly popular in Europe, and it's making inroads here in the United States. The idea is simple -- grab a bike when you need one and return it when you're done.
It's not quite so simple in execution, even when you look beyond the problems with theft and vandalism experienced by programs in Paris but, oddly, not in America.
Bike sharing has been adopted at some 400 locations worldwide. Madison, Wisconsin embraced it just last week, and Google just donated $25,000 to help Boulder, Colorado, start a program. Despite the mounting popularity, there have been some glitches. In some cases, riders haven't been able to return the bikes to the station closest to their destination because it was full. Other stations occasionally experience shortages, frustrating commuters.
Sounds like a job for mathletes.
Dr. Tal Raviv and Prof. Michal Tzur of the department of industrial engineering at Tel Aviv University have developed a mathematical model to predict which bike stations should be refilled, and when. Although the current method -- basically keeping an eye on the stations -- works well enough in a town with 100 or so stations, it falls apart in a system any larger. Using software is much more effective.
"These stations are managed imperfectly, based on what the station managers see," Raviv said in a statement. "They use their best guesses to move bikes to different locations around the city using trucks. There is no system for more scientifically managing the availability of bikes, creating dissatisfaction among users in popular parts of the city."
This is no small problem. Paris has 1,700 bike stations alone, and New York could have two or three times that many. That makes bike management a daunting, and critical, task. Raviv and Tzur are believed to be the first to use mathematical modeling to address the problem.
"Our research involves devising methods and algorithms to solve the routing and scheduling problems of the trucks that move fleets, as well as other operational and design challenges within this system," Raviv said.
Tel Aviv is deploying a bike sharing system with help from Tel Aviv University. The results of the professors' modeling could be adopted throughout Israel.
Photo of bike sharing in Melbourne, Australia: Gavin Anderson / Flickr
