Engineering Project Case Studies | Erdman Anthony

Superstructure Replacement and Roundabout

Take a flyover of the improvements to the John James Audubon Parkway bridge and adjacent roundabout.

The JJ Audubon Parkway bridge carrying southbound traffic over Ellicott Creek in Amherst, New York, had not been rehabilitated since being constructed in 1982, and a yellow structural flag had been issued for deteriorating concrete and exposed steel reinforcement every year since 2012. Similar – but less severe – deterioration was also occurring on the adjacent northbound bridge, which was built at the same time. The project site was adjacent to an intersection that was between the University at Buffalo’s North Campus’s primary dormitory complex and its educational buildings.
The Town of Amherst selected Erdman Anthony to serve as the Engineer of Record responsible for project management, preparing right-of-way acquisition maps, and all design phases for this Locally Administered Federal Aid (LAFA) project. 
The project required significant coordination with NYSDOT and the University at Buffalo. 

The final project revolved around a Complete Streets approach to accommodate both vehicles and pedestrians. The approach included a road diet throughout the project limits that reduced the number of through travel lanes to one each for northbound and southbound vehicles on JJ Audubon Parkway, to better suit the current and projected traffic levels.  
The solution included shifting both directions of vehicle traffic to a single bridge atop the southbound substructures. This allowed for the replacement of the northbound bridge superstructure with a prefabricated steel truss for pedestrians and bicyclists. The former northbound travel lanes were redeveloped with significantly less impervious pavement.
During the design, the project scope was amended to also replace the adjacent signalized intersection at Frontier Road with a roundabout. 
The project work included full-depth pavement reconstruction, milling and overlay, drainage modifications, and reconstruction of the Ellicott Creek Trailway (a popular multiuse path).

The project has improved traffic flow as well as safety for pedestrians and bicyclists throughout the project area. All existing abutments and piers were retained. The resulting road diet achieved by the realignment and movement of vehicle traffic over one bridge significantly also reduces the project area’s maintenance requirements for the Town of Amherst.

Roundabouts help solve a multitude of issues, including vehicle collisions and congestion. Learn more about how our firm knows the ins and outs of roundabouts.


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2022 ACEC New York Gold Award, Category C
Structural Systems
Catherine Gawron, PE
Catherine Gawron, PE
 716-631-1241 x 1123