New Techniques In Alinement Design And Stakeout

Old techniques of highway alinement determination, consisting of laborious field work and calculations, continue to be used in some instances to the detriment of progress. These techniques involved numerous ground measurements whereas today the use of photogrammetry, coordinate systems, computers, design templates and design tables have brought much of the work inside, resulting in faster and more accurate design. Location studies and preliminary design are conducted on topographic plans produced by photogrammetry. The final design is accomplished on paper after the chosen base line has been checked in the field. Numerous design aids, such as tables of alinement properties, special templates, and the use of whole-degree bearings, help make the design process more efficient. The design becomes a simple step-by-step process with a minimum of calculation. The procedure for interchanges differs little from that for the open highway. Alinement stakeout has been greatly simplified by the use of coordinates and electronic computers. From a series of outside control points, the center line can be laid out with little, if any, chaining.