United Fire Company Station's 3 and 31 were alerted for a collision on I-70 westbound in the area of East South Street. Enroute, the communications center advised Chief 3 that the Frederick County Sheriff's office was on the scene with a property damage collision only. Chief 3 placed the assignment in service. Chief 3-1 who was also responding on the call arrived on the scene to ensure there was no need for our services. The occupant of the State Highway Administration's truck was out of his vehicle retrieving some debris from the roadway that had become a roadway hazard. The tractor trailer driver, in an attempt to avoid a collision with other vehicles that came to a sudden stop in front of him, struck the SHA vehicle pinning the truck between the guardrail and the cab of the tractor trailer. Neither of the driver's were hurt in the collision.