Passengers on tractors, in fact, can interfere with safe operation of the tractor. The extra rider can distract the operator, block access to controls, or obstruct the operator's vision. Newer model tractors are designed to provide protection for only one person, the operator. All tractors manufactured since 1976 have a special rollover protective structure, or ROPS, that provides a safe environment for the operator if the tractor rolls over. The use of seat belts on tractors with ROPS will protect the operator from serious injuries.
Extra riders have no such protection.
There is no safe environment for extra riders on tractors. Older model tractors without ROPS can offer no rollover protection for operators or extra riders. Many people have the mistaken idea that enclosed cabs protect extra riders. This notion only gives tractor operators a false sense of security. Many tractor runover deaths happen when the child falls out of an enclosed cab.