The Washington Post reports recent regulations intended to keep air traffic controllers from falling asleep on the job have been violated nearly 4,000 times. The regulations require controllers have at least nine hours off between shifts. Internal Federal Aviation Administration documents show that more than half of the airport control towers violated this rule at least once. The regulations were implemented less than a year ago after several high-profile incidents including when pilots of a commercial jetliner had to land on their own at Reagan National Airport because the lone man on duty fell asleep.