What Forms the Best Road ?

Horowhenua Chronicle, 10 February 1914, Page 4

What Forms the Best Road ?

4 THE CEMENT VERSUS MACADAM SUItEACE. An out-of-the-way and useful controversy on roadinaking has been carried on by the Outlook, from which a letter is worth quoting that describes a highway in Michigan that has cost less than £1 per mile per year for maintenance. A striking illustration of the economic significance is as follows: "Let it be assumed that we are to build 500 miles of ordinary stone or macadam highway and 500 miles of the Michigan type . of road, the work to be done at I the rate of 100 miles a year during a period of five years, and that repairs will not be required on either type of road for a period of two years. Beginning then at the third year and estimating the maintenance costs for the Michigan road at £5 per mile per year which, it will be noted, is five times more tlicfn it really cost, the total maintenance on 500 miles of this road would, at the expiration of seven years, be only £7,500. In case of macadam, basing costs on New York and New Jersey figures, which have exceeded £LSO per mile per year, repair costs would reach the enormous total of £270,000. This amazing difference ceases to be astounding, however, when the construction of the Michigan type of road is explained. It is a simple proceeding, unattended with secrecy or patents, a precedent every community is at liberty to follow. It can be best explained in this way: Suppose we ware to pour over a highway a molten mass of bronze, and that it. could be controlled so as to Bettle into the required contour of a road some six inches thick. It would last forever. The stress of tons would be negligible. The Wayne County road builders poured over the previously shaped and rolled roadbed, a wet and mushy mass of cement, sand and stone, which hardened into imperishable rock. -lust before it hardened the surface was broomed from side itt side to give texture that keeps horses and motor cars from slipping. These roads can of themselves accumulate neither mud nor dust. They improve with age, a characteristic of concrete known to every engineeer and chemist. The Romans built roads that have lasted for centuries. Scientists discovered that their exI treme durability lay in their j binding material. Instead of holding their roads together with clay, rock-dust and' other easilydisplaced binding itmiterial, such as we use On macadam roads,..the Romans used puzzolan, a form of cement that has ke.pt also intact through centuries their wonderful buildings. The stunt* principle governs the construction, of the Michigan type of road.