A safety trailer has semi-tractor hitches at both ends and a safety wall that is fixed to one side of the trailer. That side, however, can be changed to the right or left side of the road, depending on the end to which the truck attaches. A caboose can be attached at the end of the trailer opposite the tractor to provide additional lighting and impact protection. Optionally, the trailer can be equipped with overhead protection, lighting, ventilation, onboard hydraulics, compressors, generators and other equipment, as well as related fuel, water, storage and restroom facilities and other amenities.