New York train mishap: wreck engineer suspended without pay

The train hurtled off the tracks, leaving a chain of twisted cars just inches from a river in the Bronx.

Four people died and more than 60 were injured.

While the term highway hypnosis has been around for decades, there's no technical definition of it and scant specific medical study of it, although multiple studies have found that long driving times on straight roads can cause people to lose focus.

Some experts equate highway hypnosis with a sort of autopilot state—performing a task, usually competently, without awareness of it.

Sleep experts say the daze could really be a doze, especially if a driver has undiagnosed sleep problems.

Nearly every bus or train driver has experienced the feeling of being momentarily unaware while driving long hours, said Larry Hanley, president of the Amalgamated Transit Union.

Hanley, who spent eight years driving a bus in New York, recalled spending a week on the midnight-to-8 a.m. shift and sometimes stopping to pick up passengers who weren't there.