The history of technology is replete with inventions which go through the well-known S-shaped curve of diffusion (early innovators, a phase of acceleration, a flattening of the curve when a saturation point is approached). The case of steam cars is one of those rare exceptions whose diffusion was stalled during the first of these phases. There is a limited amount of literature which examines a number of factors for this failure with the consensus being that it was the imposition of discriminatory tolls on the part of turnpike trusts which “killed” this innovation prematurely.
While acknowledging the importance of this factor, the proposed paper asks a more fundamental question that has never been posed: would steam cars have offered a more economical mode of transportation compared to stage coaches? After going through a historical narrative regarding their evolution, the study considers two types of evidence to address this question. First, it utilizes data from the only account of an actual steam car service (Dance’s venture on the Gloucester-Cheltenham road) to conclude that its heavy losses were due to gross mismanagement stemming from unnecessarily high maintenance and labor costs. By not offering a case of what the economics of steam cars ought to have been under a more rational management, the paper proceeds to consider several estimates by 18th century authors comparing the annual operating cost of the two modes. Such accounts incorporate certain caveats by omitting key cost elements. Once the gaps are addressed by the author, the conclusion is reached that a well-managed steam car company offering services to passengers could operate at c. two-thirds of the cost of stage coaches and hence it strengthens the case regarding the role played by tolls.