(1) Ruling points. These ordinarily will be (_a_) the main community centers--the large cities and villages, for to and from these will naturally flow the greatest traffic; (_b_) Natural configurations such as mountain passes, low points in hills, ridges and valleys, rivers and bridge sites; (_c_) Parks, scenery, and recreational and amusement centers; (_d_) Articulation with the highways of adjoining jurisdictions, so that they may eventually be united into one continuous passage. (2) Branch lines and detours. The question will frequently arise whether to run a branch line to some locality or detour the trunk. Much pressure will be brought by the inhabitants along the way and the deciding power will needs have firmness and fairness in the highest degree. (3) Alternate routes. If two roads of equal or almost equal importance are available a choice must be made between them. (4) Existing highways and principal streets of cities should be utilized as much as practicable. Although sometimes betterments so great may come through changes that old routes should be discontinued, in which case the (5) Vested rights of citizens living along discontinued routes and damages caused by any improvements made must be considered. (6) The widening of existing roads and streets and costs of the same. (7) The location of railways, trolley lines, and street car tracks may influence the layout for grade crossings should be eliminated, or at least placed where there is clear vision each way for a considerable distance. (8) Bridges, culverts, and railroad crossings should, preferably, be directly along the highway and at right angles to the obstruction. (9) Ruling grades, dependent upon the class of road will also affect the layout. (10) Esthetics. Perhaps the people of the United States have been too materialistic and have paid too little attention to the beauty and interest elements in highway location. Especially for pleasure riding and recreation should the esthetic side be considered. =Motor Transport Efficiency Outline.=--At this point it would be well for the road planner to consult an excellent paper by M. C. Horine and his efficiency chart which is substantially as follows:[175] ECONOMIC EFFICIENCY