A computer method of estimating the costs of bridges has been developed as part of a more general program, cosmos, that estimates the construction cost of new rural dual-carriageway roads. It consists of cost models that express the cost of a particular type of bridge as a linear function of six basic geometric parameters of the bridge. These models were derived by multiple regression analysis from data for 584 bridges. Eight cost models have been developed for over-bridges and under-bridges crossing roads, railways and rivers and having different types of deck. The new method has been shown by tests to have a satisfactory accuracy of estimation. It has proved to be less accurate in forecasting the costs of individual bridges than traditional methods at the works commitment stage in the design, but more accurate in forecasting the total cost of bridges in a contract. (Author/publisher)
Abstract