By Anne Levin

The re-opening of Rosedale Road in August, following construction of a roundabout at General Johnson Drive and Greenway Meadows near Johnson Park School, was a relief to motorists and nearby residents. The three-month project was designed to make the intersection safer for everyone, especially after a resident was fatally struck by a motorist while crossing at the pedestrian crosswalk in August 2021.

For the most part, reactions to the completed project have been positive. But some concerns aired by a few residents have prompted Princeton’s Assistant Municipal Engineer Jim Purcell to clarify some of the features, and regulations, related to the roundabout.

The project is a roundabout, not a traffic circle, said Purcell. Traffic circles were originally built to allow traffic to enter at roadway speeds. “One of the first in the world was Columbus Circle in New York City,” said Purcell. “They are large, with multiple lanes. Pennington Circle and Brunswick Circle are more local examples.”

There is some confusion about how to enter and exit a roundabout. “Vehicles entering are required to yield to those already in the roundabout,” Purcell said. “Those in the roundabout should not stop while traveling through. Not everyone knows this.”

Specifically, the Rosedale Road project is a “mini-roundabout,” which is meant to allow the majority of traffic to maneuver around the central island at a slow speed. These scaled-down versions are built in areas where a conventional roundabout cannot be constructed due to constraints such as physical obstructions or available land. Purcell specified utilities, the nearby sewer pump stations, environmentally sensitive areas, and steep slopes near Stony Brook as those constraints.

“A conventional roundabout there would have required taking land from both the Greenway Meadows Park and the open space on the north side of the road,” he said.

Roundabouts reduce crashes and slow traffic down to speeds that result in less severe results if crashes do happen. According to a statistic Purcell cites from the Federal Highway Administration, modern roundabouts reduce severe crashes at intersections by an average of 80 percent.

Before the roundabout was built, pedestrians crossing Rosedale Road often experienced difficulty. Eighty-two-year-old Pinghua Xu, the man who was killed at the site last year, had activated the pedestrian crossing signal before attempting to cross the road but was struck by the driver of an SUV.

Motorists leaving Johnson Park School during drop-off and pick-up experienced significant delays and difficulty in turning on to Rosedale Road. Risky behavior was often a result, leading to crashes.

A few residents have complained that the signs in and around the roundabout are not visible. Others have expressed concerns about speeding on approaches to the roundabout. “I go through there twice a day on my way to and from work, and I haven’t seen any problems,” said Purcell.

The basic rules of the roundabout are “Slow, Look, Yield.” There are speed reduction signs, yield signs, and pavement markings to help. “Keep looking around and checking the crosswalks to see if anyone is waiting to cross of is already crossing. Be ready to stop and let them safely finish,” Purcell said, adding that drivers must yield to traffic already in the roundabout. “Drivers and bicyclists in the roundabout have the right of way,” he said. “Bicycles can use the full lane — do not pass them in the roundabout.”