PENROSE ROUNDABOUT

THE CHALLENGE

The signalized intersection is located adjacent to the elevated I-76 Expressway and connects 20th Street, Penrose Avenue, Moyamensing Avenue, and Parker Avenue in the center of a residential neighborhood and busy commercial corridor near SEPTA’s Southern Bus Depot. The intersection was plagued with high crash rates, confusing geometry and traffic patterns, and wide crossing distances for pedestrians and cyclists making it an ideal candidate for a roundabout design.

The design effort was built on years of stakeholder engagement dating back to conceptual planning by the Philadelphia City Planning Commission in 2015. Community input including meetings with the Sports Complex Special Services District (SCSSD) and Friends of Penrose helped shape the roundabout layout and community-friendly enhancements, such as the decorative central island. A project page on the City’s website provided transparency and consistent public outreach, which helped to foster trust and engagement throughout development.

HOW WE HELPED

McCormick Taylor was reengaged in the project in 2019 when tasked with completing the final design for the new 5-leg, single-lane roundabout in coordination with the City of Philadelphia Department of Streets, the Pennsylvania Department of Transportation (PennDOT), the Southeastern Pennsylvania Transportation Authority (SEPTA), and the Delaware River Port Authority (DRPA). Our team leveraged detailed traffic data, geometric modeling, and multi-year stakeholder engagement efforts to deliver a forward-looking, context-sensitive solution.

To help the public imagine the design, McCormick Taylor’s Visualization Team created a realistic, high-quality rendering of the proposed roundabout. The rendering was created utilizing on-site photography, then integrating high-accuracy 3D survey data to precisely camera match the location and design, followed by extensive Photoshop post-processing to produce a polished final rendering that was featured on the City’s website.

The project improvements include:

• Modern Roundabout Geometry: Designed using NCHRP Report 672 guidelines, the roundabout features an inscribed circle diameter of 135 feet and a mountable truck apron for large vehicle accommodation.
• Multimodal Connectivity: An adjacent 11-foot wide shared-use path was designed to provide a safe and direct route for both pedestrians and cyclists. Bicycle lanes and ramps were connected to existing and proposed infrastructure on all approaches.
• Transit & Freight Compatibility: The roundabout was designed to accommodate city buses without using the center truck apron and modified WB-67 trucks using AutoTURN software with PennDOT-specific dimensions.
• Improved Accessibility & Drainage: ADA-compliant curb ramps, upgraded drainage systems, and improved pedestrian refuge areas at splitter islands were included to achieve compliance and provide comfort.
• Updated Traffic Control: New signage, lane separator curbs, high-visibility crosswalks, and modern LED lighting improve visibility, legibility, and driver behavior.
• Economical Pavement Design: Pavement construction minimized full-depth reconstruction and reused existing structural sections where feasible to align with cost-saving goals.

RESULTS

Construction of the Penrose Roundabout commenced in April 2024 under a $5.8 million contract funded by PennDOT’s Automated Red-Light Enforcement (ARLE) program. At the start of construction, the existing traffic signal was removed, and a temporary roundabout was installed. The contractor proceeded to build the roundabout in pieces while keeping the intersection open to cars and SEPTA buses, starting with the center island. The completion of the Penrose Roundabout was officially marked by a community walk-through and a flag-raising ceremony on June, 24, 2025.

The project directly supports Philadelphia’s Vision Zero Action Plan, which aims to advance the City’s goals of eliminating traffic fatalities and serious injuries. By replacing a dangerous and confusing intersection with a safe, intuitive and efficient roundabout, the project delivers measurable safety and operational benefits while reinforcing the neighborhood’s walkability and accessibility.

The community response has been overwhelmingly positive, including efforts to beautify the central island, which is maintained by the SCSSD, with lighting and themes inspired by South Philadelphia’s vibrant sports culture. Residents have reported smoother traffic movements and a more pleasant driving, walking, and biking experience. Additionally, the roundabout design  reduces idling time, leading to lower emissions and fuel consumption compared to traditional signalized intersections. With sufficient capacity projected for decades into the future, the Penrose Roundabout stands as a model of sustainable, multimodal, urban design.