Fast calculation of complex curve setting out elements and it´s application

At present, the mostly used linearis in the linear design of highway overpass ramp or transportation hub is complex curve which includes circular curve, completed spiral curve and incomplete spiral curve. In order to meet different needs, the form of complex curve is not the same. Some projects are made by several curve segments of different radius or curvature. So the calculation of setting out elements is very difficult. Especially in the composite linear on interchange ramp, many tedious works are needed to be done for obtaining setting-out elements. Therefore an algorithm of computing setting-out elements of composite curve is needed. In this paper the calculation algorithm of road complex curve setting-out elements was proposed and further improved, which was simply used and conveniently operated. At last, the fast calculation program was achieved using Visual Basic computer language. After examination, the program had good practical value.