By Steve Plunkett
After some back-and-forth communications between city and state transportation officials, the plan for a “diverging diamond interchange” at Interstate 95 and Glades Road is back on track.
“Our engineering staff raised a number of questions, and [state workers] have gone back and made modifications and adjustments, and talked to the staff,” City Manager Leif Ahnell said. “And I believe everybody’s happy now, and we’re all fully supportive of the project.”
In March the City Council threatened to call on its state and federal lobbyists to fight the plan after the city’s municipal services director and traffic engineer raised concerns about safety and traffic operations.
A diverging diamond interchange makes vehicles switch sides of the road at multilane X crossings guarded by traffic signals at either end of the diamond.
Paul Lampley of the Florida Department of Transportation told council members Aug. 24 that the goal of a DDI is “to improve traffic operations and system performance, reduce congestion and increase safety.”
Another benefit: The design will replace 4-foot-wide bike lanes on Glades Road to 7-foot-wide, buffered bike lanes with a 10-foot-wide “shared-use” lane for bicyclists and pedestrians in the middle, he said.
Backup generators on automatic transfer switches will be installed to power the traffic signals in case of an outage, he said, answering one of the city’s primary questions.
Other FDOT representatives said plans are also being made to convert the I-95 interchanges at Lantana Road and 45th Street in West Palm Beach to DDIs.
Design engineer Jose Otero said the Glades project will reduce crashes by 9% and reduce the severity of crashes. It will increase throughput of traffic along Glades and decrease delays, he said. And it eliminates 8,000 linear feet of retaining wall that would have been needed for a no-longer-planned “flyover” ramp.
The state agency expects work on the DDI will begin in the first three months of 2021. The schedule calls for 700 days of construction.
The Glades Road interchange is part of a $148 million project to add express lanes to Interstate 95 through Boca Raton and into Delray Beach. The overall project is supposed to open in late 2023.
In other transportation news, council members endorsed a plan to slim Federal Highway south of Southeast Mizner Boulevard from six lanes to four while adding bike lanes and widening sidewalks. Money to design that project will not be available until 2024.