OBSTRUCTION BY SNOW. In localities subject to heavy falls of snow, it is an important matter to keep the roads from be coming obstructed by it during the winter. In some countries where there is only an occasional fall of snow, as in France, it is customary to remove it from the surface of the road; but where there is much snow, it is only necessary to compact it so as to make the road pass able. This is done by driving horses or cattle back and forth along the road, or by rolling the road with a heavy farm-roller. The use of the roller should commence with the first storm of the season and be continued as often as necessary through the winter. In the case of a very heavy storm, the roller should be sent over the roads at intervals during its continuance. Obviously this work must be done by the residents along the road.
Snow and ice frequently accumulate in the side ditches to such a height as to make the surface of the road the principal line of drain age. In the spring, when this occurs on earth roads, a large volume of snow-water flows down the road, and often seriously damages it by washing gullies in the surface. Even the best broken-stone roads may be seriously injured in this way; and in some localities it is necessary to remove the snow from the side ditches to prevent damage of this character. The difficulty and expense of keeping the side ditches free from snow and ice is greatly increased, if the ditches are deep and narrow, particularly since with this form of ditch it is necessary to maintain a culvert or covered gutter at the junction of cross roads and private drives with the main highway. These culverts are very liable to become clogged with icy snow, and it is nearly impossible to clear them without digging them up— which is rarely practicable. This difficulty could be obviated, or
at least greatly decreased, by constructing shallow ditches; and, if necessary, laying a large tile drain under the ditch to carry the sur face water.
The cost of work occasioned by snow can be decreased by proper attention to the fences, underbrush, etc., along the side of the road. Snow drifts are caused by the obstruction of the currents of air near the ground—those that carry the drifting snow. In forests the winds do not have sufficient velocity to carry the snow, and conse quently it lies evenly and of a uniform depth; but in the open country it drifts with the wind. Fences and shrubbery which retard the winds but permit the snow to blow through, cause the snow to pile up on the sheltered side and possibly to block the road and ditches. The fences should be either entirely open or very close. A high tight fence obstructs the wind, and causes the snow to pile up on the windward side. If the roadside is partially ob structed, the wind moves the loose snow into earth cuts and also into the beaten snow path, and fills them up. Filling the snow trackway gradually raises the traveled portion of the road until turning out into the loose snow becomes dangerous.
In Vermont, "in many townships the cost of keeping the roads passable in the winter is one third; anti in' some one' half, of the total amount expended on the highways, and the average' for the state is one eighth," or $4.30 per mile per annum.* The possible cost of maintenance on account of snow should be considered in locating a road (see § 93).