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able to make a more careful study of some certain sections of road and this may be done by waking over the section in question in order to make a more deliberate survey of the features to be considered than is possible when riding in a motor car. Factors other than relative lengths of routes will obviously determine the cost of improvement and the comparative merits of the improved roads. Some special characteristic of a road, such as bad railroad crossings or a few bad hills, may eliminate a route, or availability of materials along a route may offset disadvantages of alignment or grade. In special cases, complete surveys of routes may be required finally to select the best route, but these instances are few in number. =Road Surveys.=--When a road has been definitely selected for improvement, a careful survey is made to furnish information for the preparation of the plans. This will consist of a transit survey and a level survey. The transit survey is made by running a line between established corners following the recorded route of the road, or if no records are available or the road is irregular in alignment, by establishing arbitrary reference points and running a line along the center line of the existing road or parallel thereto. The topography is referenced to this line in such completeness that it can be reproduced on the plans. The level survey consists in taking levels on cross sections of the road at one hundred foot intervals, and oftener if there are abrupt changes in grade. Special level determinations are made at streams, railroad crossings, intersecting roads or lanes and wherever it appears some special features of the terrain should be recorded. From the surveys and such other information as has been assembled relative to the project, a plan is prepared which embodies a design presumed to provide for an improvement in accordance with the best highway practice. THE PROBLEM OF DESIGN It will be convenient to consider separately the components of a road design, although in the actual design the consideration of these cannot be separated because all parts of the plan must fit together. =Alignment.=--The alignment of the road is determined to a considerable extent by the existing right-of-way, which may follow section lines, regardless of topography, as is the case with many roads in the prairie states, or it may follow the valleys, ridges, or other favorable location in hilly country. I
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