BRUNSWICK CIRCLE EXTENSION MODERN ROUNDABOUT

Phase: Construction (Anticipated Start: Mid-Summer 2024)

Purpose and Need: Improve safety and traffic operations at the intersection of Princeton Avenue and Brunswick Circle Extension, with a focus on vehicular, pedestrian and bicycle safety.

Traffic Impact: Construction is estimated to last for 12 months and will be completed in four (4) stages. Traffic will be maintained along Brunswick Circle Extension (CR 645) and Southbound Princeton Avenue (CR 583) throughout the project. The first three (3) stages of construction will detour Northbound Princeton Avenue motorists to the Brunswick Circle. A separate truck detour will re-route trucks during stages three (3) and four (4) of construction. Construction will impact the daily commute and we advise the public to seek alternative routes.

Proposal: Mercer County is working to convert the Princeton Ave & Brunswick Circle Extension intersection into a modern roundabout.  This acute 'Y' intersection with stop control on only one move has a high frequency of sideswipe and encroachment crashes, especially on Princeton Avenue as northbound drivers make late lane selections, and southbound drivers make turn-preparation weaves. Crashes at this intersection are much higher than the statewide averages for similar intersections. Pedestrian and cyclist crossings are currently difficult if not impossible.

• A single-lane, three-legged modern roundabout is the proposed solution at the intersection of Princeton Avenue (CR 583) and Brunswick Circle Extension (CR 645).  The proposed improvements for this intersection include the following:
• Design of a 3 leg single lane modern roundabout with 12’ lane widths on all approaches and a 16’ wide circulating lane.
• Each approach will be designed to have a concrete splitter island to provide pedestrian refuge, assist in controlling speeds, guide traffic into the roundabout, physically separate entering and exiting traffic streams, and deter wrong-way movements.
• An 8’ Concrete Truck Apron will be provided to accommodate turning movements for larger vehicles.
• Each pedestrian crossing will be marked with appropriate signing and striping as outlined in the most recent version of the MUTCD and will consist of compliant ADA design features.
• All approaches will be signed and striped per MUTCD guidelines to provide appropriate advanced notice of the roundabout.
• 4’ Concrete sidewalks will be provided along the northern edge of the project (Along Princeton Ave) to match the existing sidewalk and tie into the proposed cross walks.
• 6’ Concrete sidewalks will be provided along the southern edge of the project to connect to the existing sidewalk network. 
• Separate bike ramps are also provided for those bicyclists that choose not to navigate the roundabout and instead leave the roadway
• An 8’ asphalt or concrete shared used path will be provided along the southern edge of the project to connect the bike lanes along Princeton Avenue which will allow cyclists to leave the pavement and ride around the roundabout.
• Bicycle safe grates will be used on every proposed roadway drainage inlet.
• Landscaping will be provided within the Roundabout central island and at other locations upon further determination by Lawrence Township and Mercer County.
• Drainage facilities will be designed and installed to comply with Stormwater Management Rules and Regulations.

Additional Resources:

Public Information Center Meeting PowerPoint

BCE Roundabout Striping and Signage

Modern Roundabouts Design Basics (English)

Modern Roundabouts Design Basics (Polish)

Crash Map

Public Information Center Recorded Meeting (click here or on image above)

         - Spanish Transcript       - Polish Transcript

Public Information Center Recorded Meeting - Princeton Avenue(CR583), Mulberry St., and Trenton

Farmers Market Intersection Improvement Project -- Lawrence, NJ (click here or on image above)