The Fast and the Less Furious: 25th Street South Roadway Reconstruction and Bridge Widening

Background

Fargo is North Dakota’s largest city and has become a booming retail and events hub with traffic surges well beyond other communities of its size. Located in the heart of Fargo’s fully developed southeast residential and commercial corridor is 25th Street South. In recent years, 25th Street and the interchange at I-94 had become increasingly congested and dangerous, requiring a creative solution in the developed corridor.

The City of Fargo retained HEI and sub-consultant Alfred Benesch & Company to widen a one-mile segment of 25th Street South, reconstruct the I-94 interchange, and design a new eastbound (EB) on-ramp, the latter of which was based on an Interstate Justification Report completed by Benesch.

The Project

The roadway itself was widened from four-lanes to six-lanes, significantly reducing delay times and improving 25th Street’s level of service. The bridge was also widened to accommodate the two additional lanes. HEI increased the bridge’s width more than 50 feet from 83 feet to 134 feet.

With I-94 running directly under the bridge, it was imperative HEI maintain the bridge’s vertical clearance to meet state and Federal Highway Administration requirements. HEI installed smaller beams, which were able to maintain the clearance.

Ensuring Safety

Safety became another major concern for the project. The EB on-/off-ramp intersection proved to be dangerous with frequent crashes between vehicles turning from northbound (NB) 25th Street onto the EB loop ramp, as they had to cross the congested southbound (SB) traffic.

A new EB on-ramp allows NB traffic to enter the interstate without crossing SB traffic. HEI relocated the pedestrian crossing one block south to a conventional signalized intersection providing a safer crossing than one next to the EB off-ramp where motorists were focused on SB traffic, not pedestrians.

Aesthetic Elements

Sloping along the edge of the roadway expansion would have encroached almost to the walls of a notable and succcessful restaurant in the area, all but eliminating its green space. HEI protected the restaurant’s landscape by incorporating a five-foot high gravity retaining wall curved around the property’s edge.

This wall not only prevented the slope from intruding on the restaurant, but it added an aesthetic element that had not existed before. HEI designed another far more substantial wall to create a new on-ramp for NB 25th Street traffic entering EB traffic onto I-94.