A contract worker for the Illinois Department of Transportation (IDOT) was killed Tuesday morning by an automobile that veered into into a highway striping truck on Interstate 64 (I-64) near O'Fallon. Three other workers were injured in the accident, two of whom were airlifted to an area hospital in critical condition, according to the Illinois State Police.

The man who died was identified Tuesday afternoon as Dennis J. Beard, 48, of Pocahontas, Ill.

Eyewitnesses indicated the automobile driver was weaving through traffic at irregular speeds before steering around construction signs and striking the IDOT vehicle on the road's inside shoulder. An account by the Associated Press indicated workers were standing on or around a truck mounted attenuator, preparing to begin work, when the automobile hit them at an estimated speed of 50 to 60 mph.

The workers were employees of Briteway Striping Services, a New Baden, Ill., -based enterprise that contracted with IDOT to paint new stripes on I-64, IDOT spokesman Josh Kauffman told reporters.

The conditions of the automobile driver is unknown. Investigators indicated they planned to test the driver for drug and alcohol impairment.

The speed limit in Illinois work zones is 45 mph, regardless of whether workers are present. Motorists speeding in work zones are subject to a $375 fine for the first offense and $1,000 for subsequent offenses. If a motorist strikes a worker, the motorist faces a fine of $10,000 and 14 years in prison.

On average, more than 7,000 work zone motor vehicle crashes occur in Illinois each year, according to IDOT. In 2011, 24 people, including two construction workers, were killed in Illinois work zones.