The nation's top railroad official said Thursday his agency wants to issue new regulations to prevent human errors that cause train wrecks.

Joseph Boardman, head of the Federal Railroad Administration, said the proposed regulations would eliminate problems like improperly positioned track switches, rail cars being pushed without a safety check and having rail cars obstruct nearby tracks.

The agency also is researching railroad worker fatigue and wants to analyze close calls - incidents that nearly cause train accidents.

"People would expect today that we as an industry exceed expectations on safety," Boardman told a group of students studying to be conductors. He made the announcement after a visit to CSX Transportation's state-of-the-art training center in Atlanta.

The agency expects to publish the proposed regulations for public comment in September.

Boardman, who has more than 30 years' experience in the railroad industry, said human errors are responsible for 38 percent of the nation's train accidents. He said human error was responsible for the January 2005 freight train wreck and chlorine leak near Graniteville, S.C., the deadliest train accident involving hazardous material in nearly three decades. That accident killed nine people, injured 250 and forced 5,400 to evacuate.

In that crash, workers left a track switch in the wrong position. That caused a Norfolk Southern train to smash into parked railroad cars on a side track, rupture a tanker and spew chlorine gas into the tiny mill village.

But workers fresh out of training typically don't have such accidents. Boardman told the students to be especially careful five years into their career, the time period that studies say most train worker-related accidents happen.

"You probably will be as safe as anybody the first four or five years because you'll be remembering your training," he said.