Highways and Gravel Roads I PDF

This article needs additional citations for verification. A branch British Columbia Ministry of Forests forest service road in steep terrain. A highways and Gravel Roads I PDF road is a type of unpaved road surfaced with gravel that has been brought to the site from a quarry or stream bed.


Författare: Monika Borthwick.
MoWuKnuffels?
Das ist die liebevoll zusammengefasste Crew eines Wohnmobils.
Als Frau alleine? Im Wohnmobil? Rund zehntausend Kilometer auf endlosen Highways und Schotterstraßen? Quer durch die USA und Kanada?
Nichts leichter als das, wenn man zwei so treue Begleiter zur Seite hat wie Wuschel und Knuffi. Da wird selbst ein Weg von New York bis nach Alaska nie langweilig.

Compared to sealed roads, which require large machinery to work and pour concrete or to lay and smooth a bitumen-based surface, gravel roads are easy and cheap to build. The gravel used consists of varying amount of crushed stone, sand, and fines. Fines are silt or clay particles smaller than . Crushed stone is used because gravel with fractured faces will stay in place better than rounded river pebbles.

A gravel road is quite different from a ‚gravel drive‘, popular as private driveways in the United Kingdom. This uses clean gravel consisting of uniform, rounded stones and small pebbles. In Africa and parts of Asia and South America, laterite soils are used to build dirt roads. Gravel roads require much more frequent maintenance than paved roads, especially after wet periods and when accommodating increased traffic. As long as the process is interrupted early enough, simple re-grading is sufficient, with material being pushed back into shape.

Segments of gravel roads on grades also rut easily as a result of flowing water. When grading or building the road, waterbars are used to direct water off the road. As an alternative method, humps can be formed in the gravel along the road to impede water flow, thereby reducing rutting. Another problem with gravel roads is washboarding — the formation of corrugations across the surface at right angles to the direction of travel.

They can become severe enough to cause vibration in vehicles so that bolts loosen or cracks form in components. Grading removes the corrugations, and reconstruction with careful choice of good quality gravel can help prevent them reforming. The inferior surface of gravel is not an issue if the road is covered by snow and ice for extended periods. These are most often found near intersections as stopping or braking causes them to form or otherwise if heavy farm or other equipment often uses these roads.