In the period 1825–9, Gurney designed and built a number of steam-powered road vehicles which were intended to commercialise a steam road transport business—the Gurney Steam Carriage Company. His vehicles were built at his Regent's Park Manufactory works, and tested around the park's barrack yard, and on frequent excursions to Hampstead, Highgate, Edgware, Barnet and Stanmore, at speeds of up to 20 miles per hour (32 km/h). Gurney is by no means the only pioneering inventor in the history of steam road vehicles – Luke Herbert, in his 1837 "Practical Treatise on Rail-Roads and Locomotive Engines", rebuts in scathing fashion claims made for Gurney in preference to Trevithick as inventor of the steam carriage: