In the period 1825–9, Gurney designed and built a number of steam powered road vehicles, amongst the first designed with the intent 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 was by no means the only inventor working in this field — Luke Herbert, in his 1837 Practical Treatise on Rail-Roads and Locomotive Engines rebuts in scathing fashion claims made for Gurney in preferece to Trevithick as inventor of the steam carriage:
"…it is a matter of fact, that Gurney's carriages, made in every essential respect after Trevithick's models, did, occasionally, run [on the public roads]; and so did the carriages of many other locomotionalists; some prior, some subsequent to Gurney; some decidedly superior to his, and all those that were inferior, were incapacitated from proceeding beyond preparatory trials, by want of that material with which gentlemen of fortune, then unacquainted with steam locomotion, had so lavishly furnished on Mr. Gurney."
One of his vehicles was sufficiently robust to make a journey in July 1829, two months before the Rainhill Trials, from London to Bath and back, at an average speed for the return journey of 14 miles per hour — including time spend in refuelling and taking on water. His daughter Anna, in a letter to The Times newspaper in December 1875, notes that "I never heard of any accident or injury to anyone with it, except in the fray at Melksham, on the noted journey to Bath, when the fair people set upon it, burnt their fingers, threw stones, and wounded poor Martyn the stoker". The vehicle had to be escorted under guard to Bath to prevent further luddism.
The steam carriage was not a commercial success. There was an understandable apprehension on the part of the public to a conveyance atop a dangerous steam boiler; seeking to overcome this objection, Gurney designed an articulated vehicle, termed the Gurney steam drag, in which a passenger carriage was tethered to and pulled by an engine. At least two of these were built and shipped to Glasgow around 1830. According to the Steam Club of Great Britain:
The first was sent by sea to Leith, but it was damaged in transit. It appears that this carriage was left in Scotland while Gurney returned to London for spares. He gave instructions for it not to be used, but it was transferred to the military barracks where it was steamed and a boiler explosion ensued, severely injuring two people. The second carriage may have run a service for a short time but it remains unclear whether any passengers were carried for money. The local press carried the story of the explosion.
The remains of one of this pair rests in Glasgow Museum of Transport, to which it was presented, having been found in a barn near the Paisley Road. Again, according to the Steam Club of Great Britain, it comprises:
an almost complete chassis with the engine, some pipe work, the valve gear and the steering gear. The wheels, boiler and bodywork are missing. The whole is painted red and this has made photography difficult but appears to have preserved this item, as it is untouched since arriving at the Museum in 1889!
A regular service was established by between Cheltenham and Gloucester by Sir Charles Dance, running four times daily, for a number of months and based on a fleet of three of Gurney's carriages; but the aspirations of Dance and Gurney were effectively dashed, according to Francis Maceroni in his 1836 book A Few Facts Concerning Elementary Locomotion
The many wealthy horse-coach proprietors, together with the narrow minded country gentlemen and magistrates of the district, who erroneously conceived their interests threatened by the substitution of steam power for horse, formed one of the most disgraceful and mean conspiracies against a national undertaking that can be well remembered. By means of parliamentary intrigue, and false representations, these despicable persons obtained certain local turnpike bills to pass "the Honourable House" establishing tolls on steam carriages, which amounted to a virtual prohibition on their use.
A charge of £2 was levied on each steam carriage journey, whilst the toll for a horsedrawn carriage was 2 shillings. This may be contrasted with a contemporary exchequer loan to the railway developers of £100,000. Maceroni continues:
In addition to this flagrant outrage against justice and utility, the worthy squires and magistrates of the Cheltenham district, suddenly, without any necessity, covered a long tract of the road with a layer of loose gravel, a foot deep, which, adding to the above-mentioned difficulties an impediments, put an entire stop to the undertaking.
At the same time, press coverage of an accident befalling a Glasgow steam drag adversely affected the reputation of the vehicles. Gurney was bankrupted with debts of £232,000.
Sufficient was the concern about Gurney's bankruptcy, and sufficient were his contacts, that a House of Commons select committee was convened from 1831 to 1835 on Mr.Goldsworthy Gurney's Case. Its final report stated:
"Mr Goldsworthy Gurney was the first person to successfully operate steam carriages on common roads, and he took out patents for his invention in 1825 and 1826-27. In 1830 Mr Gurney entered into contracts with various individuals for the commercial exploitation of his invention, carrying passengers at a lower fare than horse carriages. In 1831 more than 50 private bills were passed by Parliament imposing prohibitive tolls on steam carriages (two pounds or more, while horse carriages might pay six shillings or less), and the contractors suspended their operations, pending a petition to Parliament. A select Committee was appointed, and concluded that steam carriages were safe, quick, cheap, and less damaging to roads than horse carriages, that they would be a benefit to the public and the prohibitive tolls should be removed. A bill to this effect was passed by the Commons but rejected by the Lords.
Mr. Gurney, having kept open his factory until this point was forced to close it and sell off his materials and tools at a loss. The contractors withdrew from the business.
The effect of the Acts passed by Parliament have been to make an otherwise profitable business no longer viable. Mr Gurney's losses included the costs of keeping his workshop open for six years, loss of contracts, loss of mileage duty on the various routes and the costs of patents. He also lost the advantage of being the first to develop a working steam carriage, as others used the intervening period to develop their own machines, and lost his advantage over the railways. The total loss can be calculated at over £200,000. This left him unable to either build and operate steam carriages, or to protect his patents.
Sections of those Acts imposing prohibitory tolls on steam carriages should be immediately repealed, and such tolls should be replaced by those for which horse carriages are liable. Mr Gurney's patent should be extended at public expense for a period of fourteen years beyond the date of its expiry, or a sum of not less than £5000 should be offered to Mr Gurney in lieu of such extension. Other parties have an interest in Mr. Gurney's patent, and half of the money or benefits should be kept aside for Mr. Gurney exclusively."