Johns Hopkins Magazine -- April 1997
Johns Hopkins Magazine

APRIL 1997



S C I E N C E    A N D    T E C H N O L O G Y

What is Location Science?

Charles ReVelle's first published foray into the field of location science came in 1970, in response to a problem raised by President Lyndon Baines Johnson a few years earlier. "LBJ was talking about locating hospitals specializing in heart, cancer, and stroke throughout the country, and the question was, Where should they go?" recalls ReVelle, Hopkins professor of geography and environmental engineering.

Using a branch of mathematics known as optimization, and a tool called linear programming, he devised a model that incorporated population centers as "nodes," and found subsets where the hospitals could be placed so that the average distance that people would travel would be as small as possible. The resulting paper, "Central Facilities Location," has become a classic in the field.

When his first paper was published, ReVelle was one of only a handful of people doing work in location science. Today, driven by public policy needs and advances in computer technology, he says, the field is drawing interest from researchers in a variety of disciplines: economists, civil and electrical engineers, geographers, urban planners, and operations research scientists. And ReVelle couldn't be happier.

A gentle man with twinkling eyes and salt-and-pepper beard, Chuck ReVelle approaches location conundrums with an enthusiasm that his students and colleagues find infectious. Rather than flipping through a magazine when he's waiting for a plane, ReVelle amuses himself by tinkering with an especially vexing problem (one that's kept him busy the last year is the Roman legions problem.)

In addition to being passionate about the science of siting, ReVelle is also prolific. He's written or co-authored more than 150 journal articles and six books (including five environmental textbooks co-written with his wife, Penelope). Last fall he was a co-recipient of the first Lifetime Achievement Award in Location Analysis from the Section on Location Analysis at the Institute for Operations Research and the Management Sciences.

Over the years ReVelle has proposed the best places to open power plants, ambulances, firestations, pipelines, and warehouses. With a colleague, he was selected by the Department of Energy during the Carter Administration to find the safest and most efficient routes for transporting spent nuclear fuel rods. He's helped Baltimore City officials to see whether effective fire protection could be provided with fewer fire stations. Together with his students, he's even shown how to design compact, cost-efficient nature preserves that allow the greatest number of species to survive.

As computer technology has advanced, ReVelle says, "we've been able to solve larger and more sophisticated problems. Initially, using a mainframe computer, we could do problems involving 20 to 30 nodes, or population centers. Today we can tackle problems involving thousands of nodes, and we can do it on a desktop."

Currently, ReVelle is collaborating with colleagues around the globe on problems involving everything from forestry management to designing road networks in developing countries. -- SD