ROAD PLAN

Figure 3-3.—The road plan. The drawing of the proposed center line is then given to a final location party, which stakes in the center line and curves. With the approval of the engineer, the party chief may make changes in alignment of the center line, but the changes must be recorded. Once the final location is determined, all information and changes pertinent to the location are used to prepare a second and final drawing, showing the final center-line location, construction limits, all curves and curve data, station marks, control points, natural and man-made terrain features, trees, buildings, and anything else that is helpful in construction. This drawing, known as a road plan (fig. 3-3), is a “bird’s-eye view” of the road and shows what you should see from a position directly above. The road plan is drawn on the upper portion of plan-and-profile paper, using any scale desired. The bottom portion of the plan-and-profile paper, which, as you know, is composed of grid lines, is reserved for drawing the road profile. ROAD PLAN The road plan, or location and length of plan view, shows the actual the road measured along the center line. The length is determined by station points, which are set at full station (full stations are 100 feet or 100 meters apart), half station, or one-tenth station intervals. Odd-station points are set at major breaks in the terrain. Referring to figure 3-3, you see the manner in which the beginning station (0 + 00) is shown, and you also see the manner in which the full stations and the partial stations are shown. Recalling your study of the EA3 TRAMAN, you know, then, that the distance from 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 on the plan if they are in the right-of-way or construction limits. (Right-of-way is the land acquired for the road construction.) Identification and location of these objects are taken from the surveyor’s notebook Their location is determined by a station number and distance from the center line. All measurements and distances are made perpendicular to the center line of the particular station unless otherwise noted. Horizontal Curves The road center line consists of straight lines and curves. The straight lines are called tangents, and the curves are called horizontal curves. These curves are used to change the horizontal direction of the road. All information necessary to draw a curve should be furnished by the engineer or taken from the surveyor’s notebook. The necessary information is known as curve data. Below is the data for curve No. 1 in figure 3-3 and an explanation of the terms. D = 56°00' D = 23°00' R = 240.11' T = 132.53' L = 243.48' 3-3