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

Is there not much injury done to the roads by the heavy weights both of coaches and waggons?—I am not disposed to think that upon a well-made road the weight of coaches is material, or that it would be judicious to make any legal provisions affecting that subject. In regard to waggons, I conceive that the loads carried upon wheels of the description encouraged by recent acts of parliament, whatever their weight, would be very little injurious to well-made roads. I think a waggon wheel of six inches in breadth, if standing fairly on the road with any weight whatever, would do very little material injury to a road well made, and perfectly smooth. The injury done to roads is by these immense weights striking against materials, and in the present mode of shaping the wheels they drive the materials before them, instead of passing over them, because I think if a carriage passes fairly over a smooth surface, that cannot hurt the road, but must rather be an advantage to it, upon the principle of the roller.

Are you not of opinion that the immense weights carried by the broad-wheeled waggons, even by their perpendicular pressure, do injury by crushing the materials?—On a new-made road the crush would do mischief, but on a consolidated old road the mere perpendicular pressure does not do any. But there is a great deal of injury done by the conical form of the broad wheels, which operate like sledging instead of turning fairly. There is a sixteen-inch wheel waggon which comes out of Bristol, that does more injury to our roads than all the travelling of the day besides.

Are you of opinion that any benefit arises from those broad-wheeled waggons, which would justify their total exemption from tolls?—None at all.

Does the answer you have given to the Committee relative to the effect of great weights, apply equally to roads made with gravel, as well as broken stone?—I mean it to apply to all well-made roads, whether of gravel or of other materials.

You mean after the road is smooth and solid?—Yes.

But with regard to a new road, are you not of opinion that the materials are crushed and worn out by a great weight?—Yes; no doubt that is so on a new-made road, and one of those waggons with the wheels made conical, would crush a greater proportion of stone than it ought to do.

Do you not conceive that the state of the turnpike roads would be improved by not allowing any waggons to carry more weight than four ton?—I don’t know that that would make any great difference, under good management. I think the defect lies in a want of science in road-making.

Martis, 9° die Martii, 1819.

John Loudon MᶜAdam, Esquire, called in; and Examined.

In your evidence last week, you stated that less improvement had taken place in the roads in the neighbourhood of London than in any other district, to what causes do you attribute this circumstance?—I consider the principal cause to be the small extent of the trusts, and the peculiar situation of London, which increases the bad effects of the division into very small trusts.