FRANKFORD-TRENTON-YORK ROUNDABOUT

PHILADELPHIA, PA

This project demonstrated that a compact urban modern roundabout can be built low-cost, within the constrained right-of-way, with public support, and still accommodate trucks and buses.

DESIGN , COMMUNITY, INFRASTRUCTURE

THE CHALLENGE

The Frankford Avenue, Trenton Avenue, and York Street intersection located in Philadelphia's Fishtown neighborhood was one of four locations identified in a 2016 feasibility study focused on High Injury Network locations in the City. This location was prioritized to advance into design and construction to reduce the roadway footprint and simplify the complexity of the former signalized intersection.

 

The 6-legged signalized intersection is located in a dense, urban environment and the existing configuration was difficult to navigate and had low signal-head visibility given the absence of signal mast arms.

 

The overall goal of the project was to demonstrate that a low-cost urban roundabout could be constructed within the existing right-of-way, be more pedestrian friendly, and reduce speeds, emissions, and risk of severe and fatal crashes.

 

existing intersection
Existing intersection
photo 3 roundabout under construction april 2021
Roundabout construction, April 2021
photo 2 central island during construction
Central island during construction
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View from Trenton Avenue

HOW WE HELPED

McCormick Taylor completed the final design for the new roundabout in coordination with the City of Philadelphia Department of Streets; the Office of Transportation, Infrastructure, and Sustainability (OTIS); and the Pennsylvania Department of Transportation (PennDOT).

 

The geometric design includes ADA curb ramps, drainage, and roundabout components including splitter islands, truck aprons, and a main central island. Through the progression of design, it was decided to regrade half of the intersection in order to provide a curb reveal and ADA-compliant sidewalk slopes in the vicinity of an outside truck apron on Frankford Avenue. This project required PennDOT’s review and approval in the form of a Highway Occupancy Permit (HOP) Submission.

 

Frankford Avenue is a state route with an Annual Average Daily Traffic (AADT) ranging from 8,500 to 9,000, while the other roadways have lower volumes. Truck movements at the intersection greatly impacted the geometric and operational design decisions. This led to a unique design aspect in that the central island was designed so large trucks can traverse the island if needed. The central island design was therefore intended to be mountable for tractor trailers and constructed with reinforced plastic composite material under soil and grass to allow trucks to go over it without causing ruts or potentially having their trailers get stuck. Additionally, no signs were placed on the central island.

RESULTS

This project supports the City’s Vision Zero goals, namely to reduce traffic fatalities to zero. When compared to a signalized intersection, roundabouts have been shown by PennDOT to reduce traffic crash risk, suspected serious injury crashes being reduced by 76%, and total number of crashes decreasing by 9%.

 

The project improvements include:

  • Roadway and roundabout enhanced LED lighting
  • Speed cushions to slow motorists on the approach of the roundabout on York Street and planned for construction on Frankford Avenue
  • New signage and pavement markings
  • Enhanced accommodations for trucks and buses approaching the intersection
  • Grass mountable central island 
  • Entry points designed to slow vehicles
  • New sidewalks and ADA ramps

Overall, the reaction from the public has been very positive and has sparked some unique uses including a pre-opening roller disco, a wedding photo backdrop, and even its own Facebook fan page. Building a modern roundabout that is urban, compact, and within the existing right-of-way has made the intersection safer for all users. Additionally, a recent news article highlighted the fast-paced redevelopment that is occurring at this one intersection just in the past year.

 

AWARDS

2022 Project of the Year, MASITE

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Aerial view of the roundabout
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Speed cushions on York Street approach
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Enhanced LED lighting