WEDNESDAY, Dec. 4, 2013  — On Sunday, a Metro-North train took a turn at 82 miles per hour — nearly three times the 30 MPH speed limit — and derailed, killing four passengers and injuring more than 60 others. As the victims’ families mourn, everyone is trying to understand what caused the accident, and on Wednesday, several reports surfaced explaining that the driver, William Rockefeller, 46, had “zoned out,” or may have been experiencing “highway hypnosis,” according to a Reuters report.

But for two sleep experts observing the case, the probable cause was obvious: the driver was simply sleep deprived.


A microsleep is a short burst of sleep can last as short as 1 second or as long as 30. A person’s eyes can remain open and he or she may think nothing has happened, but it’s the result of being too tired on the job, and it’s a major contributor to all kinds of traffic accidents, Dr. Rosenberg said.

"Highway hypnosis" isn’t a medically recognized term, but the distracted, fatigued phase it suggests most likely means the person wasn’t getting enough sleep, said Michael Thorpy, MD, director of the Sleep-Wake Disorders Center at Montefiore Medical Center in New York City.

“There are countless examples of major catastrophes that have happened because people are sleepy,” Dr. Thorpy said.

Rockefeller had been up and at his post for several hours already that day when the crash occurred at 7:20 am. Because Rockefeller’s workday starts before 6:30 am, he officially classifies as a shift-worker, meaning he works an unusual shift that likely affects his ability to sleep normal hours, Thorpy said.

Shift workers have a higher risk of falling asleep on the job, because they have a much more difficult time getting adequate sleep. Part of this is because it’s consistently difficult to get enough rest when one is forced to sleep during unnatural times, such as during daylight hours. Another issue, according to Thorpy, is that while shift workers adhere to their irregular schedule on their working days, they tend to go back to a more normal schedule on their days off, going to bed at 11 pm and sleeping until 7 or 8 am. Because of this, they never truly adjust to their shifted schedule, and are more likely to be sleep-deprived.

Metro-North announced that Rockefeller had a full 8-hour sleep the night before the crash, and had also driven the same route two days earlier. But that only tells part of the story, Rosenberg said, noting that he had been a night-shift worker just a few weeks before, and had only recently been driving this early morning route.

“When he was driving, that was a time that a few weeks ago, he was in a deep sleep,” Rosenberg said, noting that the body needs more time to adjust to a new sleep schedule.

Furthermore, even if Rockefeller slept well the night before, that doesn’t necessarily mean he was well-rested, Thorpy said. Even though he had driven the past two days, if he had been off the day prior to that and had not adhered to his early-morning schedule, it would be more likely he was tired, Thorpy said.

Furthermore, Thorpy said that based on the photos of Rockefeller he saw, the driver may have sleep apnea or another sleep-related breathing disorder, which is very common in middle-aged men who are overweight. This could have doubled his risk of being tired, Thorpy said.

There are several things that could have helped in avoiding such a crash, both researchers said. For one thing, it’s important for shift workers to stick to their adjusted schedule as much as they can, rather than revert to a normal schedule on days off, Thorpy said. Light often affects how well people can sleep during the day, but wearing orange-tinted glasses to block blue light could help prepare someone to rest during daylight hours.

Additionally, for high-risk jobs like driving, having more than one person at the controls can help prevent accidents, which is part of the reason two pilots are in the cockpit during airline flights, Thorpy said.

New crash avoidance technologies could help avoid future accidents, Rosenberg said.

If you’re setting off on your own holiday voyage, remember that even if you’re not a shift worker, it helps to be well-rested. Don’t plan to drive during the hours when you would normally be in deep sleep. If you get tired, take a break. Get off the road and either walk around, take a short nap, or drink a cup of coffee, Rosenberg advised.

“Don’t try to keep driving with the windows down and radio on loud,” Rosenberg said. “If you’re going to go into the microsleep stage, that’s not going to keep you awake.