NEWARK, Del. — Delaware transportation officials are warning motorists to keep windows closed and avoid unnecessary stops because of honeybee swarms near a highway ramp where a tractor-trailer carrying hives overturned.

The ramp to Interstate 95 in Newark reopened Wednesday, more than 12 hours after the rig carrying 460 hives with an estimated 16 million to 20 million bees from Florida to Maine crashed Tuesday. Police cited the driver, 55-year-old Adolfo Guerra of Miami, for unsafe shifting of load or cargo.

Police say Guerra and two passengers were taken to Christiana Hospital with minor injuries from the crash and 50 to 100 stings each. There were reports of passers-by being stung.

State police spokesman Sgt. Paul Shavack says three on-call bee handlers worked with firefighters to spray water to disperse and calm the bees.

State police have had an official honeybee swarm removal plan for 14 years and this is the first time they used it, Shavack said.

“There’s no rounding them up,” Shavack said of the bees. “The water will disperse and calm the bee activity.”