to receive in cooperation with an aperture formed in the accessory mounting post 36 an accessory locking pin 110 the elevated crossbar 60 has first and second ends 62 64 and a longitudinal center 66 a mounting post 68 is vertically attached to the longitudinal center 66 the mounting post 68 is inserted into the upper end 56 of vertical post 52 to mount the elevated crossbar 60 atop the vertical post 52 lamp assemblies 40 are attached to the first and second ends 62 64 of the elevated crossbar 60 another accessory that may be mounted to the accessory mounting post 36 is a safety strobe assembly 100 shown in fig3 the strobe assembly 100 includes a strobe light 102 attached to a strobe support post 104 the strobe support post 104 is a tube having an inside diameter sufficient to fit over the accessory mounting post 36 for support an aperture 106 is formed through the strobe support post 104 to receive in cooperation with the aperture formed through the accessory mounting post 36 the accessory locking pin 110 wiring harness 80 is provided to connect the lamps and accessories to vehicle power connector 82 allows for a fast electrical connection to the vehicle power and will typically be connected to the vehicle 39 s reverse lighting power so that the lamps are illuminated when the vehicle is put into reverse gear fig5 a 5b and 5 c show.