Brief design and numerical calculations for a secondary road

Abstract

Based on the traffic volume survey, the standard traffic volume conversion is considered, and then the road traffic volume is predicted. Through the calculation, the maximum annual average daily traffic volume in the design life is obtained, and then the road grade and design speed of the design road are determined. The Annual Average Daily Traffic (AADT) is converted into Directional Design-Hour Volume (DDHV), and then the number of lanes of the road is determined. Collect the terrain data of the route area through the field survey, and then carry on the interior design. The route schemes are compared and the optimal route scheme is selected. AUTOCAD and a professional road design software were used to assist in the design of road line selection, horizontal curve design, vertical section design, cross section design and drainage design. Through the calculation, the design parameters such as the maximum synthetic slope, the average slope and the minimum length of superelevation transition section are obtained. Afterwards, the parameters in horizontal curve, vertical curve and superelevation-widening were checked manually.