The 43-year-old man, a contractor for Amalgamated Construction, had been resurfacing a road under a railway bridge in Brigg on 24 June when the incident occurred.
The man was taken to Scunthorpe General Hospital, where he later died.
A HSE spokeswoman said it was unsure exactly how the accident happened, but it is believed the vehicle’s brakes had not been secured after a section of the work had been completed.
The death of a 67-year-old man last month at Devon has now also been classified as a construction fatality.
The man had been thatching a farm roof in Tiverton on 27 May when he fell and sustained serious injuries.He was admitted to hospital, but died on 2 June.
The HSE are investigating both incidents.