Remarks on the Present System of Road Making / With Observations, Deduced from Practice and Experience, With a View to a Revision of the Existing Laws, and the Introduction of Improvement in the Method of Making, Repairing, and Preserving Roads, and Defending the Road Funds from Misapplication. Seventh Edition, Carefully Revised, With an Appendix, and Report from the Select Committee of the House of Commons, June 1823, with Extracts from the Evidence

by John Loudon McAdam

What are the particulars of the situation to which you allude?—The situation of most of the roads near London is very low, difficult to be kept free from water, the traffic is very great both in weight and number, and therefore requiring more skill, as well as more care and attention, than the other roads of the kingdom; the material found near London for making the roads is gravel of a very bad quality, it is mixed with an adhesive loam that cannot be separated from the gravel, except by the united power of water and friction; this operation cannot be effectually performed before laying it on the roads, but is done by the rain and the traffic, producing a stiff mud, which is not only in itself an impediment to travelling, but has the effect of keeping the roads loose; the form of the gravel is also unfavorable, being smooth round masses of flint, without any angles by which the parts might unite. On the other hand, London is placed in a situation peculiarly convenient for being supplied with materials from a distance, by water carriage. The materials that may be so procured are of the very best description, and, under the sanction of parliament, may be procured on very moderate terms. The Thames furnishes gravel of a very good quality and quite clean; by using this gravel, the navigation of the river will be improved; the several canals, the Surrey, the Grand Junction, Paddington, and river Lea navigation, present facilities for procuring clean flint of the best kind; the coast of Essex, Kent, and Sussex, can furnish a supply to any extent of beach pebbles, one of the best road materials in the kingdom. Granite chippings might be obtained occasionally from Cornwall, Guernsey and Scotland, as ballast; two pieces of road were made with these materials near London, without any mixture of land gravel, at Blackfriars Bridge and Westminster Bridge.

What are the impediments which, in your opinion, prevent the commissioners of the roads near London from availing themselves of those advantages?—The very small trusts into which the roads in the immediate vicinity of London are divided, is the principal cause; this renders it impossible for commissioners to enter upon the plan of procuring materials upon an extended scale, and they cannot be obtained with any regard to economy, except in quantity, with a view to a supply for the whole roads, proceeding from the stones of London to a certain distance. There are also some impediments arising from particular laws, regulations and customs, which can only be removed by parliament. The Ballast Act gives a right of pre-emption to the Trinity House of all stone and other materials brought as ballast into the Thames. The coasting duty on stone operates as a prohibition to the importation of stone as merchandize; the amount of canal duties payable on merchandize prevents the carriage of road materials on all inland navigations; manure so transported has been protected in most Canal Acts, but road materials have not been considered. Should parliament be pleased to remove these difficulties, the London roads may be rendered independent of the gravel of the country, by a moderate exertion of statistical and mercantile information on the part of the officers employed by the commissioners.

If the Committee understand you right, you give a decided preference to materials thus imported, over the gravel to be found in the neighbourhood of London?—I do.

Is it your opinion, that by proper regulations a sufficient supply of those materials to which you have alluded, could be procured for the whole of the roads in the neighbourhood of London?—Yes, I think there might; because a steady and constant demand, even at a low price, would insure importation, and this demand can only be steady if the roads round London were consolidated under one set of commissioners acting for the whole, and having depôts into which they could receive materials at all times at a fixed price, to be distributed wherever wanted, by an assurance of a ready purchaser; vessels coming in ballast, or not fully loaded, from any place where good road materials were to be procured, would be induced to take on board sufficient to make up their loading; contracts could also be made for flint by the various canals, and upon terms more moderate than the present price of gravel; I am unable to lay before the Committee a detailed plan for supplying the London roads with good and cheap materials, which requires a considerable time and attention in the inquiry.

Is there any other information connected with the improvement of the roads in the neighbourhood of London, which you think you could give to the Committee?—I am quite satisfied that the materials to be imported into London would make good roads, because I made two pieces of very excellent road with those materials at the two bridges, without making use of any gravel of the country.

At what time was this done?—The pieces of road were made in August and September 1817.

What was the extent?—There were about 200 yards of the one, and about 180 yards of the other; one of them joins the iron pavement at the foot of Blackfriars bridge; and the other joins the Marsh-gate turnpike, and goes to the Asylum; those roads were made with river-gravel and pebbles from the coast.

From whence did you get the river-gravel?—It was purchased from the steam-engines that raise it in the river.

Did you lift the old road?—I took up all the stones that were in them that were good for any thing, the flints and other stones, and then made use of a considerable quantity of additional materials to make the surface of the road afterwards.

Was the expense considerable?—There was no account kept of the expense of the experiment at Westminster bridge, because the commissioners wished me to employ a number of paupers and persons that had been on the road before, without discharging them, who were very indifferent hands; and they also wished that the road should be very considerably above the level than I thought necessary, and that brought much more materials than otherwise need have been put on; but the Blackfriars bridge experiment cost about seven-pence halfpenny per square yard; there was a very correct account kept of it, including the price of materials and labour, and every thing.