ANTIOCH -- An Antioch man who crashed his motorcycle into a drainage ditch remained in critical condition Tuesday morning, police said.

Police spotted the motorcyclist speeding through a residential area on Auto Center Drive around 10:30 p.m., then watched as he purposely left the roadway to drive along the railroad tracks near the road, Antioch police Sgt. Mike Hulsey said.

The officer who saw the motorcyclist began searching the tracks on foot after the driver did not reappear. He found the motorcycle and the driver in the ditch, Hulsey said.

An ambulance was called to the scene, and the driver was taken to a hospital with serious injuries, Hulsey said. Police are not releasing the man's identity.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH.