The truck hit the pedestrian around 8:30 p.m. between Twin Rivers Drive North and Probasco Road, East Windsor police said.
Initial reports said the pedestrian was in traumatic arrest.
He was taken to Robert Wood Johnson University Hospital in New Brunswick in New Brunswick with life-threatening injuries.
A 22-year-old motorist from Hainesport in Burlington County, who was driving the truck, stopped and has not been charged.
All lanes of Route 33 were closed during an investigation by East Windsor police and the Mercer County Prosecutor’s Office.
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