To smoothly and surely perform a towing and driving even when a large heavy object is transported in a friction drive trolley conveyor in which a traveling body 1 for transportation having a friction drive load bar 5 with engagement means 32 for towing at both ends in the longitudinal direction is used.

The engagement means 32 for towing comprises a shaft to be engaged 35 laterally horizontally installed in a vertical cutout part 44 formed at one end of the load bar 5, a hook member 33 vertically swingably supported on a vertical intermediate position of the load bar 5 at the other end of the load bar 5 and engageable with and disengageable from the shaft to be engaged 35 of the load bar 5 of the traveling body 1 for transportation adjacent thereto, and a holding means for holding the hook member 33 selectively in an engaged attitude or a disengaged attitude. A first selector means 45 for changing the hook member 33 from the engaged attitude to the disengaged attitude and a second selector means 47 for changing the hook member 33 from the disengaged attitude to the engaged attitude are disposed in a traveling path.