Abstract: A safety cart for use by repair persons along a travelled highway is constructed of heavy steel plate to carry cones, flags, and an illuminated sign from the repair vehicle up the road to warn approaching motorists of the work site. The cart is carried to the site while attached to the front of the repair vehicle and a support device is attached to the front of the vehicle which tilts down out of the way of the forwardly tilting engine hood. The cart includes a pivoting handle which pivots to bring an engaging rod upwardly to a height of mounting slots in the supporting device on the vehicle. The handle is then used as a lever to lift the safety cart upwardly to abut the support device on the vehicle to be releasably interlocked on the support device.