Precast or cast-in-place segmental cantilevered construction forms a relatively new generation in US bridge construction. One of the largest-scale projects of this kind is the I-205 Columbia River Bridge in Portland, Oregon, which was started in 1979 and is due for completion in 1982. The project consists of two parallel bridges, each 75 ft wide. Its final contract for the main superstructure (length of 5770 ft) was awarded to a joint venture of SJ Groves and Guy F. Atkinson. Responding to the Oregon Department of Transportation's policy of value engineering, the longer 480-, 600-, and 480-ft spans were changed from precast to in-place construction by using traveling wagons; the shorter 240-, 300-, and 360-ft spans remained precast. This unique setup afforded a special opportunity for comparing the two construction methods and for coordinating design and geometric control with construction. Included in this paper is an outline of geometric control for both cast-in-place and match-cast segments; methods for predicting deflections, which consider shrinkage and creep; and a brief description of computer programs for cantilevered construction. Also included are a description of the coordination between designer and field personnel in order to achieve quality and accuracy in construction, a comparison of actual constructed elevations with predicted elevations, and, finally, a discussion regarding implications for future segmental construction.(Authors)