A work assist vehicle includes a self propelled, steerable body having a chassis and a drive mechanism supported on the chassis; a mast assembly coupled to the body; and, a personnel compartment attached to the mast assembly and being movable by the mast assembly toward and away from the body. The body further includes a cover adapted to extend over a portion of the chassis and a weight sensor assembly coupled to the chassis and the cover. The weight sensor assembly is capable of detecting if someone or something is located on the cover.