One of the major highway interchanges in the south Denver metro area is set to undergo construction, starting in the coming months, in a project that hopes to better accommodate traffic on two of Englewood's largest roads.

During the construction to replace the aging South Broadway bridge over U.S. Highway 285, traffic on Broadway could be reduced to one lane in each direction, according to the City of Englewood’s online updates on the project.

The project will ultimately add a third lane in both directions under Broadway on Highway 285. In Englewood, that road is synonymous with Hampden Avenue in some parts and with Jefferson Avenue where the highway dips to the south.

Construction is expected to begin in spring or summer 2022 and continue through the end of 2023, according to the city’s website. The project’s design phase started in December 2020 and lasted into early 2022, the website says.

The Broadway bridge was completed in 1955, and the ramps were completed in 1970, according to Jake Warren, the project manager for Englewood.

“Bridges built in the (1950s) and 60s had a typical service life of about 50 years,” Warren told Colorado Community Media last year. “Modern bridges are designed with an anticipated service life of 75 years.”

The project gives the city an opportunity to improve other elements on the Broadway bridge, according to the website.

Those improvements may include wider sidewalks, a “buffer” zone between pedestrians and traffic, “improved aesthetics,” and narrower lanes promoting safer driving as traffic enters the pedestrian-dense downtown Englewood area, the website says.

The new bridge could include the updated Englewood logo on four large, decorative columns at the corners, the website adds.

Upon receiving some remaining approvals from the Colorado Department of Transportation, or CDOT, the project was to go to the Federal Highway Administration for approval, according to a March 31 update from the city.

Here’s more information on the project and what it could change.

Traffic shifts

During construction, when traffic may be reduced on Broadway to one lane in each direction, the new lane pattern could eliminate the southbound-to-eastbound left turn and set up a detour for the eliminated movement, according to the city’s updates.

A permanent change to traffic may occur nearby. To eliminate weaving and provide a “safe zone” for traffic merging onto eastbound Highway 285, access to Highway 285 from Sherman Street to the south would be fully removed, the website says.

Sherman Street at the north side of Highway 285 may become fully closed, or a right turn off westbound Highway 285 onto Sherman could be included, Warren said last year.

For cyclists and pedestrians, that would mean the traffic light and street crossing at Sherman Street would be removed. Cyclists and pedestrians would be rerouted a short distance east to the Little Dry Creek Trail.

Handling water

The National Environmental Policy Act, or NEPA, established the requirements and processes that federal agencies must consider regarding the environmental effects of Federal Highway Administration proposals and actions, according to an overview from that federal agency online.

For recipients of federal funds, that means that before proceeding with final design and construction, a project must first disclose any environmental consequences and evaluate alternatives that would avoid or lessen the project’s impacts, according to the overview.

The environmental resources that were to be considered or evaluated as part of the NEPA approval process for the Englewood project included air quality, noise and permanent water quality, among others, according to Warren.

“Given that we’ll have additional surface area from the extra lanes on 285, we’ll include stormwater detention, such that there isn’t an increase from historic flows being sent directly into Little Dry Creek,” Warren said last year.

The proposed water quality mitigation measures — which will likely include both hydrodynamic separators and rain gardens — will help remove pollutants and improve the quality of stormwater runoff discharged into Little Dry Creek, a February update from the city said.

The city contracted with the engineering firm ATKINS North America, referred to as “the consultant,” to perform environmental investigations regarding the project and to develop plans and specifications for construction, the city’s website says.

More info

The project draws from three sources of funding, including $7.6 million in federal funding, $0.8 million from the state and $1.7 million from the city, according to the updated total online.

The city hosted public information meetings about the project. The meetings took place in February 2021, May 2021 and in October, according to the city’s website.

See more information on the city’s project webpage at tinyurl.com/EnglewoodBroadway285.