Figure 3-3.—The road plan.The drawing of the proposed center line is thengiven to a final location party, which stakes in the centerline and curves. With the approval of the engineer, theparty chief may make changes in alignment of the centerline, but the changes must be recorded.Once the final location is determined, allinformation and changes pertinent to the location areused to prepare a second and final drawing, showing thefinal center-line location, construction limits, all curvesand curve data, station marks, control points, natural andman-made terrain features, trees, buildings, andanything else that is helpful in construction. Thisdrawing, known as a road plan (fig. 3-3), is a“bird’s-eye view” of the road and shows what youshould see from a position directly above. The road planis drawn on the upper portion of plan-and-profile paper,using any scale desired. The bottom portion of theplan-and-profile paper, which, as you know, iscomposed of grid lines, is reserved for drawing the roadprofile.ROAD PLANThe road plan, orlocation and length ofplan view, shows the actualthe road measured along thecenter line. The length is determined by station points,which are set at full station (full stations are 100 feet or100 meters apart), half station, or one-tenth stationintervals. Odd-station points are set at major breaks inthe terrain. Referring to figure 3-3, you see the mannerin which the beginning station (0 + 00) is shown, andyou also see the manner in which the full stations andthe partial stations are shown. Recalling your study ofthe EA3 TRAMAN, you know, then, that the distancefrom the beginning station to the last full station shown(13 + 00) is 1,300 feet.All man-made and natural objects, such as trees,buildings, fences, wells, and so on, are also plotted onthe plan if they are in the right-of-way or constructionlimits. (Right-of-way is the land acquired for the roadconstruction.) Identification and location of theseobjects are taken from the surveyor’s notebook Theirlocation is determined by a station number and distancefrom the center line. All measurements and distances aremade perpendicular to the center line of the particularstation unless otherwise noted.Horizontal CurvesThe road center line consists of straight lines andcurves. The straight lines are called tangents, and thecurves are called horizontal curves. These curves areused to change the horizontal direction of the road. Allinformation necessary to draw a curve should befurnished by the engineer or taken from the surveyor’snotebook. The necessary information is known as curvedata. Below is the data for curve No. 1 in figure 3-3 andan explanation of the terms.D= 56°00'D= 23°00'R = 240.11'T = 132.53'L = 243.48'3-3
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