Abstract: A motorized vehicle for effecting a spraying operation onto an elongate structure (e.g. a roadway crash barrier) as the vehicle travels alongside said structure has an arm extendable transversely of the vehicle and provided with spray means for effecting said spraying operation associated with means for following the elongate structure so that the spray is always directed towards the structure. The vehicle also has a tank for holding a medium to be sprayed by the spray means, and means for supplying said medium under pressure to the spray means.