Grand Ave Bridge

The Grand Avenue Bridge project will replace the existing bridge in Glenwood Springs, Colorado, US. The $125.6m project also includes the construction of a new pedestrian bridge.

Replacement of the bridge is essential to ensure connectivity between Glenwood Springs, the Glenwood Hot Springs district, and Interstate 70. The project will also promote public safety by providing emergency service response.

Construction of the project commenced in January 2016 and is expected to be completed by 2018.

Grand Avenue Bridge project purpose

The replacement project is being undertaken as the existing bridge is functionally obsolete. The existing bridge consists of nine spans with three steel units of concrete pier foundations. It has insufficient vertical and horizontal clearances and has a 55% of load carrying capacity.

It also has four narrow 9ft, 4in lanes instead of the standard 12ft, with no shoulders. The deck and girders of the bridge do not also meet the current design standards.

"Construction of the project commenced in January 2016 and is expected to be completed by 2018."

Replacement of the bridge is aimed at widening the existing lanes, improving the load of the deck and girders, as well as promoting clearance at 7th Street and the Union Pacific Rail Road.

The project also includes the construction of bicycle and pedestrian pathways on either side of the river.

Design of the Grand Avenue Bridge replacement

The existing bridge is being replaced with a new four-lane bridge with modifications made to its alignment. The new bridge will comprise 12ft-wide lanes with a striped median for large vehicles. Two feet-wide shoulders on the east and four feet-wide shoulders on the west will be also be provided.

The southbound left turn lane will be extended and the lane widths between 7th and 8th Streets will be reduced to 11ft to fit into the existing lanes downtown.

A five-leg roundabout at the 6th Street/Laurel Street intersection will also be constructed to minimise traffic between I-70/SH 82, 6th Street, and Laurel Street. The fifth leg of the roundabout will be a one-way southbound lane connecting to the Exit 116 interchange.

A traffic signal will be installed at the 8th Street and Grand Avenue intersection to control traffic movements.

New pedestrian bridge and bicycle facilities

A new pedestrian bridge will replace the existing pedestrian bridge, which will also carry utilities line across the Colorado river. The bridge will include a pedestrian plaza to provide a connection to 6th and 7th Streets.

A new grade-separated path starting from the existing Two Rivers Park Trail will be built to replace the existing connection. New pathways and crossings will also be constructed at the 6th Street/Laurel Street intersection.

Grand Avenue Bridge construction

Construction on the Grand Avenue Bridge project is being carried out in five phases. South and north causeways are being constructed to provide access to both the piers of the new bridge and the pedestrian bridge.

Phase one of the project includes construction of southern causeway, cul-de-sac at the west end of the Glenwood Hot Springs parking lot, and installation of utilities on the 7th Street and Wing Street. It also includes installation of a temporary footpath, cassion and substructure work.

Construction of south causeway was completed in March 2016. The temporary walkway was opened in March 2016 and the old pedestrian bridge was demolished in April 2016.

The second phase includes construction of a road route, walls of river road and some of the I-70 westbound off-ramp. A pedestrian tunnel, cassions, drainage systems and a pedestrian building at 7th Street will also be constructed.

The new pedestrian bridge is expected to be opened in March 2017. Construction of the north causeway across the Colorado river is scheduled to be completed in August 2017. The 6th and Laurel Roundabout, River Street, SH 82 and I-70 Exits and construction of the new bridge are scheduled for completion in December 2017.

The construction of Glenwood Hot Springs Lot is expected to be completed in February 2018, while the causeway will be removed in March 2018.

Contractors involved

The Granite/RL Wadsworth Joint Venture (JV) was appointed as the construction manager / general contractor (CMGC) for the project. The total value of the contract is $76m.

Jacobs Engineering is providing consultancy services for the project, while Tsiouvaras Simmons is the designer of the new bridge. AMEC Foster is responsible for designing the pedestrian bridge.

Newland Project Resource (NPRI) received a contract to provide project management services. Other subcontractors involved in the project are SGM, Gould Construction, PR Studio, United Companies, Cal-X Minerals, Grand River Construction, S2M, Pioneer Steel, and Your Way Safety & Signing.

Financing for the Grand Avenue Bridge project

Colorado Bridge Enterprise, CDOT, utility companies, and local governments, including the City of Glenwood Springs ($3m), Garfield County ($3m), and Eagle County ($300,000) are collectively providing $125.6m for the project.