The collision occurred shortly after 2 a.m. when the SUV hit the loading bucket of a John Deere tractor at Cove Road and Federal Highway, Florida Highway Patrol Lt. Chris Cribbs said.
The names of the three victims, all from Palm Beach County, were not released. The driver of the tractor was not injured, The Palm Beach (Fla.) Post reported.
"In the area where the crash occurred there's not much light," Cribbs said. Members of the construction crew, however, said the tractor itself was well lit.