This series looks at the different type of road steam engine - loosely referred to as traction engines - in each of their different guises, including showman's engines, traction/general purpose engines, steam rollers, road locomotives, wagons, ploughing engines and portables - each covered across multiple editions, taken in manufacturer alphabetical order from Allchin to Wallis & Steevens. Pictures contrast the engines as they were in their working days through to early preservation and how they are today. Each edition has 100 pages of mostly previously unpublished pictures with detailed captions and an historical overview of the products of each company.