The 15-year-old driver of a car that struck and seriously injured a Dane County sheriff's deputy Friday afternoon on Highway 151 near Sun Prairie was stopped minutes earlier by a Madison police officer who briefly pursued the vehicle after it sped off as the officer approached, authorities said.

The male deputy, whose name had not been released Friday pending notification of family, was in stable condition Friday night at UW Hospital with nonlife threatening injuries.

The deputy was placing spikes in the road in an attempt to stop the vehicle when the driver swerved and struck him at 2:09 p.m, said Sheriff's Office spokeswoman Elise Schaffer.

It was not known if the driver intentionally struck the deputy or swerved to avoid the spikes, Schaffer said.

The driver was arrested by the State Patrol at 3:30 p.m. on Interstate 94 east of Johnson Creek in Jefferson County after a chase that reached speeds of 110 mph, said Sgt. Tanya Connors. Authorities are not releasing his name because he is a juvenile.

He was being held Friday night in Dane County Juvenile Reception Center. Madison Police Sgt. Shawn Engel said the driver is not from the Madison area.

Madison police spokesman Joel DeSpain said that at 1:57 p.m., a supervising sergeant called off a 70-mph pursuit of the driver on the city's Far East Side after about a minute, deeming it unsafe.

At the time, Madison police did not know that the vehicle was stolen, said Lt. Carl Strasburg.

The vehicle, a black 2006 Dodge Stratus, is believed to have been stolen in Stoughton earlier Friday, Schaffer said.

The deputy was taken by helicopter to UW Hospital. "He was conscious," Schaffer said. The extent of his injuries was not known Friday night.

A portion of Highway 151 northbound was closed for about an hour while the State Patrol investigated the crash, Connors said. Traffic was delayed for another three hours after one lane was reopened.

Madison police had received a 911 call from someone reporting an erratic driver who possibly was intoxicated on Stoughton Road, Strasburg said.

An officer located the vehicle and followed it on Milwaukee Street before stopping it on Sprecher Road, but the car sped off as the officer approached, police said.

DeSpain said the officer didn't see anything that would have justified continuing the pursuit in afternoon traffic. "Our officer did not observe the erratic driving," he said. "It was just going to be a routine traffic stop."

Strasburg said that in such cases, police normally would follow up on violations later by tracing the car's license plate.

Madison police notified Dane County authorities that they had terminated their pursuit and that the vehicle was nearing the area patrolled by the Sheriff's Office, Strasburg said. "We leave it up to their jurisdiction to decide what to do with (the information)," he said.

Lt. Brian Hayes of the Dane County Sheriff's Office said a deputy in the area spotted the vehicle and began pursuit on Sprecher Road in the town of Blooming Grove about 2 p.m.

"We felt the driver was reckless," Hayes said, adding that it was thought to be a "greater danger to the public if we let the suspect go."

Generally what happens with such pursuits is another deputy will try to safely set up spikes to stop the driver, Hayes said, adding, "You're never really safe ... when you're trying to put spikes out with somebody who doesn't want to stop."