Investigators believe the semi-truck was speeding on Interstate 55 near Channahon when it struck several vehicles stopped in a construction zone, state police Cmdr. Randy Ness told reporters after Monday's crash. Federal regulators have been tightening rules on work hours for commercial bus and truck operators and are seeking to curtail the practice of logbook tampering to ensure compliance and keep fatigued drivers off the nation's roads. In March, the Federal Motor Carrier Safety Administration proposed that trucks and buses crossing state lines be equipped with electronic devices that record how many hours the vehicles are in operation.