A Safer Circle

For drivers in Hamilton Township, NJ, White Horse Circle is more akin to a maze than an intersection. The tangle of lanes at South Broad Street, White Horse Avenue, and Route 206 is difficult to navigate, congested, and dangerous — there were more than 160 crashes in a three-year period.  NJDOT began exploring ways to improve safety at the circle during earlier projects and Urban developed conceptual designs for several options, including the modern roundabout selected for construction.

Our evaluation covered physical features and roadway deficiencies along with access, zoning, and land use plans. We used VISSIM to analyze conceptual alternatives in light of current and forecasted traffic conditions. Alternatives included modifying circulation patterns, installation of a signalized intersection, and conversion of the circle into a modern roundabout.

Services included

• Mapping
• Pavement Design
• Utility Management
• Civil and Traffic Engineering
• Environmental Studies
• Cost Estimating
• Construction Phasing and Scheduling
• Preparation of Construction Documents

New Perception of Roundabouts

An early challenge was gaining public support for the roundabout and acceptance of the higher costs associated with this solution. There are few modern roundabouts in New Jersey and the public is often skeptical about their effectiveness.

Design challenges centered on developing a 12-month construction schedule. We worked with NJDOT, Mercer County, and Hamilton Township to create a multi-staged traffic control plan with limited detours. 

New Layout Offers Host of Improvements

We designed a single/double lane hybrid roundabout, 170 feet in diameter, with 16-foot-wide lanes. Each approach has a splitter island and the White Horse Avenue and South Broad Street approaches both include crosswalks. Reconstructed and resurfaced pavement; improved drainage, including landscaped swales to convey stormwater; installation of curbs and ADA-compliant ramps; and use of grass areas where there was once asphalt are among the improvements provided by the new layout.

Rather than cutting through the circle, vehicles on Route 206 use approach, circulating, and exit lanes for northbound and southbound travel, yielding to traffic within the roundabout. Signing and striping enforces these new traffic controls.

To gain support for this design, we provided presentations and handouts to help the public better understand the benefits of modern roundabouts. We also explained the positive impacts construction of the White Horse roundabout will have on various communities.

Roundabout as Gateway

The roundabout will serve as an aesthetically pleasing gateway into Hamilton Township. It also provides a smooth transition from the multilane highway section of Route 206 heading north into the roundabout to the streetscape section of Route 206 in Hamilton Township.

Highlights

• Multi-lane modern roundabout design
• Public involvement
• VISSIM and AutoTurn modeling
• Analyze roadway deficiencies and substandard conditions
• Pedestrian and ADA-compliant access
• Multi-Stage traffic control with minimal detours
• Coordination with several utility companies for relocation of aerial facilities to underground facilities