SAN JOSE, Calif. â€"  A doctor says a man found seriously injured in the brush a week after his pickup truck rolled off a Northern California freeway is making progress.

Michael Sanchez Jr. has been hospitalized since he was found unconscious Tuesday in a dense thicket below an off-ramp along Highway 101 in south San Jose.

Authorities couldn't find the 25-year-old driver after the crash, but he was located a week later when they went back to search for clues about what happened to him.

Despite the medical report, questions remained about why he wasn't found during a search of the scene after the May 8 crash.

"We were looking all over for this gentleman," CHP Lt. Les Bishop told the San Jose Mercury News. "We not only searched the immediate area and the brush, but we checked the shoulders on the freeway, the neighborhoods and the adjacent park."

Bishop told KTVU-TV it was a diligent, thorough search.

"It wasn't just 45 minutes of standing around," he said.

Bishop said witnesses reported that a man had climbed out of the overturned truck and left the area before the CHP arrived. Bishop did not immediately return a call from The Associated Press seeking further comment.

Dr. Bruce Wilbur told the station Thursday that Sanchez was initially in a coma and unresponsive, but has made significant progress.

"He was on a respirator and the respirator was completely responsible for his respiration, but now he is breathing spontaneously," Wilbur told the station.

Wilbur said he was not sure how Sanchez managed to walk away from the crash and then apparently collapse.

"He did suffer some sort of blow to the head," said the doctor.

The discovery of Sanchez came about a week after members of the California Highway Patrol, the Santa Clara Sheriff's Department and firefighters using high-powered lighting conducted an initial search at the crash site for nearly an hour.

Family members reported Sanchez missing after he failed to show up for a funeral two days after the crash, police said. An acquaintance last heard from Sanchez on the day of the crash.

Three San Jose police detectives desperate for clues went back to the crash site Tuesday evening in hopes of finding a paper trail that might lead to him or show where he had been before the crash, Officer Jose Garcia told the AP.

Instead, they found Sanchez. It could not be immediately determined how far he was from the crash site.

"It's a miracle that he's alive," Garcia said. "They figured it was a remote possibility he was way down there out of view, but he was. It's remarkable that he survived essentially a week without any food or water. Remarkable."

Garcia, however, said the CHP did provide enough information as a result of its investigation to persuade police detectives to go down and take a second look.

"We're very fortunate that the officers took that step, even if it was for possible evidence and then they actually find him," Garcia said. "It's just good old-fashioned police work."