The incident occurred on Thursday night when four farmers were sleeping on the roadside on the highway, they said.
Twin brothers Ram and Shyam Ojha (18), and their labourer Soram Singh Saheriya (21) died on the spot while Jugdish Ojha, uncle, received injuries and is undergoing treatment at a hospital, they said.
The bodies were handed over to the kin after the postmortem, they said.
An FIR was registered for negligent driving, they said, adding the accused truck driver Rampal Jatav has been arrested.