UNIV. OF LOCATION, GRADES, WIDTHS AND CROSSSECTIONS OF RURAL ROADS The improvement of any road or system of roads must begin with a study of its location and grades, for unimproved roads are often bad in both respects. The purpose of relocation is to enable the road to carry the anticipated traffic with the least effort and loss of time. It is impracticable to relocate all roads and improve their grades at the present time, and highway officials must be satisfied with gradually eliminating or at least reducing the defective conditions. In order to carry on this work efficiently, however, the entire system of roads under a board or commission must be studied as a whole, so that the whole body of taxpayers may be benefited as uniformly as practicable by the work done annually. The work should be planned in a broad way several years in advance, if possible, for it is only in this way that the needs of all parts of the district can be met without favor or prejudice. This is particularly important where the needs are great, the road funds meager, and property has been developed along locations where roads should never have been laid out. The situation in such cases has been summed up as follows by W. S. Keller, State highway engineer of Alabama: The genuine bad roads cannot be maintained for the reason that they have never been constructed. The great amount of work necessary to keep them in passable condition disheartens the man who is by law compelled to work them. Until these roads are relocated, avoiding heavy grades and marshy bottoms, sharp angles and useless twists, and are graded so they will have good drainage, we may expect them to be bad. Location. It is evident that the road should be as nearly straight between the points it connects as the configuration of the country traversed will permit. It is desirable, however, to restrict grades to 6 per cent and to avoid expensive cuts, fills and bridges. To locate the road properly and meet all local conditions in the best manner requires competent engineering services; if they are not obtained there is a strong probability that after the country develops new locations must be made to meet the increased transportation needs and the expenditures for new rights-of-way will be far greater than to-day. But if, for the present, engineering services are out of the question, the road authorities can at least relocate roads that are plainly un RO VIMU necessarily low and marshy and unnecessarily steep and high. This is particularly the case where roads have been laid out on the section lines of the government land surveys. However desirable the rectangular parceling of unoccupied land may have been in attracting settlers, it has proved a heavy handicap on transportation by introducing many right-angle turns and causing needless length in the roads of these regions. The following comment on this condition was made by W. S. Gearhart, State engineer of Kansas: A 60-foot road on two sides of a section of land occupies 14.55 acres, while a road 60 feet wide in a diagonal direction through the section occupies 10.28 acres. Thus there is a saving in the diagonal road of 4.27 acres and 0.587 mile of distance. The saving in the cost of right of way, assuming that the land along the section line is as valuable as on the diagonal line, is $85.40 if the land is worth only $20 per acre. This amount in most cases would be sufficient to grade the 1.413 miles of diagonal line in firstclass condition. If a man lives 4 miles north and 4 miles east of his marketplace he is 5.657 miles on the diagonal line from it; that is, on the sectionline road he must travel 4.686 miles farther in making the round trip than on the diagonal line. The same official has reported that a county commission built a mile of road on a section line, which crossed the same stream three times. By adopting a somewhat different location and making the road 1 miles long, the stream would be crossed but once and the road become of greater service to the community. "More than $3,000 worth of steel bridges were bought, it will cost not less than about $2,500 for the abutments to set these three structures on, and an expenditure of $2,500 will be necessary to make the road passable, or a total of about $8,000 to accommodate four men whose property is reported as probably not worth as much as the cost of the road." Instances of this nature prove the desirability of having roads located by engineers without interference from political or personal influences. The assertion that such services are unnecessary in connection with such relatively inexpensive highways as dirt roads is best answered by pointing to the action of the Utah State road commission in substituting an entirely new location about 15 miles long for an old route in Beaver County. This was done by the engineers because the new line had better alignment, grades and road materials. The influence of soil conditions and the presence or absence of road materials may not be given due consideration in locations made by persons who are not engineers. The following comments on this point were made by A. N. Johnson in a report on the highways of Maryland: Should it happen that two locations are possible with about equal advantages and disadvantages, except that one was over a different soil from the other, that location should be taken which traverses the soil best calculated to insure a good road-bed. For example, if it were possible to avoid going through a clay section when a more open soil could be had close at hand, much would be saved both in the cost of construction and in the subsequent maintenance by going over the more open soil. It is hardly necessary to state that crossing soft, boggy soil should be avoided whenever the expense of going around such a place would be no more than for crossing it. If possible it is always well to locate a road in the vicinity of good road-material, either a suitable stone or gravel, for the proximity of such material lessens for all time the cost of maintenance of the road, and when this point is considered such a location would be warranted even at an increased first cost. Profile of new road Profile of ground at new location Profile of old road, PROFILE OF ROAD IN BALTIMORE COUNTY, MD. Showing How Relocation Saved a Large Sum in the Improvement of the Road. Value of Engineering Services.-Few persons realize that the expense of engineering services in relocating old roads is generally more than offset by the saving in the cost of construction of a properly located road over one improperly located. The engineer knows how to fit the road to the ground in hilly country so that the material from the cuts may be used in making nearby embankments and costly rock excavation will be reduced to the lowest practicable amount. On the Maryland State highways, the expense of moving 100 to 150 cubic yards of earth is from $50 to $75, which is equal to the cost of making a mile of careful surveys that may be reasonably expected to save more than 150 cubic yards of such earthwork. The accompanying illustration shows the saving in excavation expenses on a road in Baltimore County, Md. The hilly character of the old road made necessary heavy reductions in grade to give a highway properly accommodating the traffic. The heavy cutting to give suit able grades along the old location is shown by the diagram, while the light excavation and filling required on the new location is also indicated. Such savings of cost can only be made by competent engineers. The amount of detail which the engineers' survey must furnish depends on the character of the road to be built and the nature of the country. Less detail is necessary for an earth road in a flat country than a brick road in a hilly district, for example, but enough should be obtained to make sure that the final location is along the line on which the cost of transportation plus the interest on the first cost plus the cost of maintenance of the road will be the minimum for the available funds for first cost. The last point is important, for the best location is often governed by the amount of money which can be spent on construction. In carrying out extensive work by contract, experience shows that low bids from responsible contractors are best secured when full information is obtained for their use in preparing estimates. For instance, in carrying out road improvements in Vermilion County, Illinois, under a $1,500,000 bond issue, about 1800 drawings of plans, profiles and cross-sections were prepared in the first two months of the work. These were plotted on Plate A 4 by 20 profile paper cut into 32-inch lengths. The longitudinal scale of the plans was 80 feet to 1 inch and the tranverse scale 40 feet to 1 inch. The horizontal scale of the profiles was 80 feet to 1 inch and the vertical scale 4 feet to 1 inch. The plans show all section corners, bench marks, fence lines, shade trees, farm entrances, property owners' names, drains and culverts to be built, and any other data necessary for a complete knowledge of the working conditions. The cross-sections are plotted on a scale of 4 feet to 1 inch. An 11 by 8-inch map was made of the location of 14 sources of sand and gravel, the plants furnishing paving brick and the railways running from them to the district where the roads were to be built, and 24 by 20-inch maps were made showing the roads, railways and sidings available for contractors' use. The existing road grades were shown on small maps, and other small maps showed the location and size of proposed bridges and culverts. Grades. The effect of grades on hauling is usually stated in the following manner: If a horse can pull 1,000 pounds on a level road, he can pull 810 pounds with the same effort on a 2 per cent grade, 720 pounds on 24 per cent grades, 640 pounds on 3 per cent grades, 540 pounds on 4 per cent grades, 400 pounds on 5 per cent grades and only 250 pounds on 10 per cent grades. These figures are only approximate but they show the importance of reducing grades as much as possible where traffic is heavy. Where traffic is not heavy, the cost of reducing grades below 3 |