The Purple Line station in Riverdale Park will be one of the few places the planned light-rail line is elevated.

The 16-mile transit line, which will run from New Carrollton to Bethesda when it opens in 2020, mostly runs along existing roads, project manager Mike Madden told the Hyattsville Wire.

That will be the case as it passes through the University of Maryland campus, past the College Park Metro stop and through the M Square Research Park. But the line will then be elevated as it turns from River Road onto Kenilworth Avenue, as will the station at the intersection with East West Highway.

Madden said that traffic on Kenilworth was simply too high for the train to run on the roadway. The Maryland Transit Administration explored putting a tunnel, but the topography was not right in the area.

“We’d have to stay underground longer,” he said. “It’s more efficient for us to go over the intersection.”

He said both the city of Riverdale Park and Prince George’s County also supported the elevated option. After the transit line turns east onto East West Highway, the elevated line ramps down to street level again until the final stop at the New Carrollton Metro station.

Assuming the state agency gets its permits and federal funding on schedule, construction will begin on the Purple Line in 2015.