A bumpy half-mile missing link on the North Shore Trail will be filled handsomely this winter by a $5 million elevated structure stretching from near the 31st Street Bridge to the Three Rivers Rowing Association’s boathouse in Millvale.

The trail addition “is actually one long bridge along the riverbank,” said Thomas E. Baxter IV, executive director of Friends of the Riverfront, the nonprofit organization that sponsored and championed the project.

The addition is part of a $21.9 million Pennsylvania Department of Transportation project to relocate railroad tracks running parallel to Route 28 to clear the way for a major reconstruction and widening of the highway.

The project will begin soon with completion of the trail bridge scheduled for April. There will be no closure of the trail during the project, Mr. Baxter said. “We did not want to cut anyone off who commutes or uses the trail for recreation,” he said.

Until now, riders on the North Shore who wanted to continue to Millvale had to endure a rutted half-mile unimproved section across Norfolk Southern Railway property between the entrance to the Washington’s Landing pedestrian bridge and the boathouse.