Home >> A-treatise-on-roads-and-pavements-1903 >> Forms Of Construction to Setting The Telford >> Improving Old Roads

Improving Old Roads

surface, traffic and road

IMPROVING OLD ROADS. Country roads may be improved in any of several ways: 1. By changing the location, to secure better alignment or lower gradients. The method of doing this has been discussed in Art. 2, Chapter I.

2. By cutting down the hills and filling up the hollows, to secure easier gradients. A hill may be cut down without seriously inter fering with traffic by cutting one side of the roadway down a foot or two with drag or wheel scrapers ( 141), and then turning traffic on this portion and lowering the other side, continuing to cut down each side alternately until the desired depth is reached. If the earth is deposited upon the embankment in the hollow, the traffic will consolidate the road as it is built up, which is very desirable.

3. By laying tile and cutting open ditches, to improve the drain age, as has been discussed in 98-113.

4. By re-forming the surface by the use of the scraping grader, to improve surface drainage, as discussed in 145-46.

5. By adding sand or gravel to a clay road, or clay to a sand road, to improve the surface. When dry, clay makes a very hard.

and durable surface; but it absorbs water quite freely from above, and is so impermeable that it is not easily drained from below, con sequently clay roads are very bad during a wet time. Clean coarse

sand or small gravel mixed with the clay will form a hard surface that is nearly impervious to water, and consequently is not readily softened by it. Sand may be laid on in thin layers and left to be worked in by traffic; or it may be worked in with a harrow or culti vator and then rolled. Cinders may be used in a similar manner; but pebbles, the largest of which are about the size of a pea, are best for this purpose. They should be laid on in a two-inch layer and then rolled, the roadway being previously sprinkled if it is not already soft. After applying and rolling in a layer of pebbles, the road should be opened to traffic for a month or two, after which another layer should be added. Three or four layers will make a road fairly good except during a long-continued wet time. Each layer will improve the surface, but this method of hardening the surface should not be confounded with the method of constructing gravel roads discussed in Chapter III.