“BRIDGE OUT” NO MORE: The Alexander Street/Road project, replacing three bridges and closing the road for six months, is almost complete, and the road is scheduled to open on Friday, May 15. A joint undertaking of the New Jersey Department of Transportation and Mercer County, in close coordination with the town of Princeton, the project “will be fully appreciated when the stay-at-home order is lifted and we begin the return to work,” said Princeton Mayor Liz Lempert.

By Donald Gilpin

Alexander Street/Road in Princeton and West Windsor is scheduled to reopen on Friday, May 15 after six months, following concurrent Mercer County and New Jersey Department of Transportation (NJDOT) projects that replaced three bridges over the D&R Canal, the Stony Brook, and Alexander Creek.

The new bridges between Princeton and West Windsor are complete, the sidewalks are open for pedestrians, and Mercer County and the NJDOT are in the process of final paving and striping.

“It’s great to have this major project coming to a conclusion and to have the road opened back up,” said Princeton Mayor Liz Lempert. “We all benefit when necessary investments are made in our vital infrastructure, even though the disruption caused by construction can be painful.”

Princeton Municipal Engineer Deanna Stockton added, “It has been an excellent example of how the state, county, and municipality can be flexible and work together to achieve a common goal.”

Lempert emphasized the importance of Alexander Street/Road access to Princeton as one of only three main entrances to Princeton from Route 1 and the east. “This investment will be fully appreciated when the stay-at-home order is lifted and we begin the return to work,” she said.

In the context of the current pandemic the Alexander Street/Road three bridges project may not seem the high priority crisis that it seemed when it was first announced. The necessary closure, starting November 6, 2019, was of particular concern to the merchant community, as variable message boards on Route 1, Interstate 295, and elsewhere provided information about projected travel times on different routes into Princeton.

Resourceful drivers planned different timetables and routes coming into town, with some employers implementing flex time or telecommuting for employees. But it was impossible to avoid long lines of traffic and delays when traveling into and out of town, especially on Washington Road or Harrison Street — until March, when the pandemic and stay-at-home orders removed the traffic problem.

The Alexander Street/Road closure crisis was, in some ways, a warm-up for Princeton and its leaders in preparing for the coronavirus pandemic. “I’m grateful to all of our community partners who came to the table to help us work through this,” Lempert said last September when the project with its November 6 to May six-month closure was announced. “It’s painful, but it’s important to support local businesses at this time. We can get through this together as a community.”

The old bridge over the D&R Canal, the NJDOT part of the project, was built in 1948 and was in poor condition. It was a three-span, timber bridge with a timber deck overlaid with asphalt. There was a six-foot-wide timber sidewalk on each side, with one travel lane in each direction and no shoulders.

The new bridge is a single-span with a beam-supported concrete deck on reinforced concrete abutments. The outer edge of the structure and concrete wingwalls feature a wood façade, and the railings and guiderail meet current standards, according to the NJDOT. The new roadway includes two 12-foot lanes, two five-foot shoulders, and two five-foot-wide timber sidewalks with concrete curbs.

The Mercer County part of the project included replacement of the truss bridge over the Stony Brook and of the structurally deteriorated bridge just north of Basin Street over Alexander Creek. The truss bridge was installed in 1989 as a temporary replacement to the structure in place at the time. Construction of a permanent bridge became a priority as the truss bridge began to deteriorate and the width was not adequate to accommodate bus and truck traffic. Bridge railings and guiderails were upgraded to meet current standards.

Both Mercer County bridges were built with the same roadway configuration as the new D&R Canal Bridge constructed by the NJDOT, and the design of all three bridges is respectful of the historic nature of the D&R Canal and surrounding area, according to the NJDOT.

The three bridges were replaced simultaneously, using accelerated bridge construction techniques, which significantly reduced the required closure time of Alexander Street/Road from approximately nine-12 months to less than six months.

Mercer County and NJDOT coordinated with the towns of Princeton and West Windsor, with Princeton University, and with regulatory agencies such as the New Jersey Department of Environmental Protection (NJDEP), NJDEP Historic Preservation Office, D&R Canal State Park, D&R Canal Commission, and NJ Water Supply Authority.

“I want to thank the county and state for making this investment in our area, and I also want to thank everyone for their patience as the work was completed,” said Lempert. “The community should know that talks with the DOT are already underway for replacement of the Washington Road bridge. The good news for this future project is that unlike the Alexander project, it will not require a complete road shutdown, as the area is not under the same environmental constraints.”