When part of the U.S. 1 bridge north of Northlake Boulevard collapsed in October, the detour took thousands of drivers down Lighthouse Drive — and over another 60-year-old bridge that needs repairs.
North Palm Beach Special Projects Director Chuck Huff said upcoming repair work on the bridge, just east of Prosperity Farms Road, is just cosmetic. There’s some rust underneath the bridge and exposed reinforcement steel, plus the approaches to the bridge need to have fill pumped in. The village performed similar work in 2008, he said.
Still, bridge inspectors gave the Lighthouse Drive bridge a “sufficiency rating” of 27.2 percent when they examined it May.
For comparison, inspectors rated the U.S. 1 bridge at 75.8 percent in November 2015, according to Florida Department of Transportation records. Two years later, two cables failed, dropping a 90,000-pound slab of concrete sidewalk into the C-17 Canal just north of Northlake Boulevard.
Engineers use a complicated formula to determine the sufficiency rating, and a lower rating doesn’t necessarily mean the Lighthouse bridge is in worse shape, Huff said.
The rating is used to determine whether a bridge should be repaired or replaced. Only about half of the factors relate to the condition of the bridge itself, according to FDOT.
Bridges with ratings below 80 percent can get federal money for repairs, and bridges with ratings below 50 percent can get federal money to replace them.
The Lighthouse Drive bridge fared much better on the health index, a tool that measures the overall condition of the bridge, scoring a 94. Inspectors gave the U.S. 1 bridge an 86 two years before it failed. A health index below 85 generally indicates some repairs are needed, according to FDOT.
Both the Lighthouse Drive and U.S. 1 bridges were built in the 1950s, and FDOT considers them both “functionally obsolete.” That doesn’t mean the bridges are unsafe; it just means they are not built to modern road design standards.
North Palm Beach owns the Lighthouse Drive bridge, which hasn’t been properly maintained in recent years, Village Manager Andy Lukasik told the Village Council Feb. 22. A contractor will make repairs to stabilize the bridge for another eight years or so, said Lukasik, who left Jupiter last March to run the village.
“We’ll continue to invest dollars in it to keep it safe until a time that we can think about the replacement of the bridge,” Lukasik told the council.
North Palm Beach should seriously consider a plan to replace the bridge within five to eight years, according to a report from the public works director to the council.
Proshot Concrete will repair the Lighthouse Drive bridge at a cost of no more than $146,600. The money will come from the countywide penny sales tax increase that voters approved in November 2016.
The work won’t be very noisy, and it will start in about a month, Public Works Director Steven Hallock told the council Feb. 22.
One lane of traffic will stay open at all times, he said. The village will get the word out with signs, a notice on the website, door hangers, news releases and possibly knocking on residents’ doors, Hallock said.
The village expects the contractor to finish the job in 60 days, Huff said. The village will get another bridge inspection report this year, after the work is done.
It will take much longer for FDOT to replace the U.S. 1 bridge. It had been carrying six lanes of traffic, with sidewalks on either side of the bridge before the partial collapse. It’s down to four lanes for cars, with the outermost lanes reserved for walkers and bicyclists.
FDOT estimates construction on a $5 million project to replace the bridge will start in 2023, spokeswoman Barbara Kelleher said.