Mercer County is considering roundabouts at two intersections along Pennington-Lawrenceville Road as part of a broader study aimed at improving safety for motorists, pedestrians and bicyclists along the busy corridor through Hopewell and Lawrence townships.
The county will present proposed roundabouts for the intersections of Pennington-Lawrenceville Road (County Route 546) with Federal City Road/Stephenson Road and with Blackwell Road during a public information meeting Sept. 22 at Stony Brook Elementary School.
The two intersections are among three along a 1.6-mile stretch of Pennington-Lawrenceville Road being examined as part of a county Local Concept Development study. The third is the intersection of Pennington-Lawrenceville Road, Federal City Road and Keefe Road.
All three intersections are currently signalized.
The study is intended to address what engineers describe as safety and operational deficiencies for all road users, including motorists, bicyclists and pedestrians. The project team includes representatives from Mercer County, the Delaware Valley Regional Planning Commission, New Jersey Department of Transportation and consulting firm IH Engineers.
Study identifies pedestrian and safety concerns
The county’s preliminary work has identified a number of issues at the three intersections, including inadequate traffic-signal timing, gaps in sidewalks, limited pedestrian crossings, substandard roadway features and insufficient signage.
At Pennington-Lawrenceville Road and Federal City Road/Keefe Road, engineers found pedestrian ramps that do not meet current Americans with Disabilities Act guidelines and are not suitable for wheelchair users.
Similar deficiencies were identified at the Federal City Road/Stephenson Road intersection, where crosswalks are provided on only two approaches and curb ramps are limited.
At Pennington-Lawrenceville and Blackwell roads, the study found no crosswalks, bicycle facilities, ADA ramps or sidewalks.
Traffic counts taken in June 2024 found that all three intersections generally operate at a Level of Service B during peak periods, although the northbound left-turn movement at the Federal City Road/Keefe Road intersection falls to Level of Service E during the afternoon peak.
Safety is also a focus of the study. Engineers reviewed crash data from January 2021 through December 2023 and found no pedestrian or bicycle crashes at the three intersections during that period. Right-angle crashes accounted for 28% of recorded collisions and rear-end crashes for 22%. About 78% of the crashes among the three locations occurred at the Federal City Road/Keefe Road intersection.
Roundabouts among alternatives being studied
The county is evaluating changes that could include modifications to intersection approaches and lane configurations, traffic-signal upgrades and timing changes, left-turn phases and modern roundabouts.
The township’s Sept. 10 announcement specifically identifies roundabouts as the proposed improvements for the Federal City Road/Stephenson Road and Blackwell Road intersections.
The work remains in the concept-development stage rather than final design. Engineers are collecting and analyzing existing conditions, identifying the project’s needs and developing alternatives. Those alternatives will then be evaluated before a preliminary preferred alternative is selected.
The county’s traffic analysis anticipates a possible 2029 construction year and will evaluate projected traffic conditions through a 2049 design year.
Public meeting Sept. 22
Mercer County will hold a public information meeting on the project at 6:30 p.m. Tuesday, Sept. 22, at Stony Brook Elementary School.
The county is seeking public input as it develops and evaluates potential improvements for the corridor.
