Two girder designs are under consideration for a bridge to cross a span of 1,350 feet. The first design is expected to result in superstructure weight per foot of 14(S)+1,500. The second should result in a superstructure weight per foot of 17(S)+1250, where S is the span between piers. Piers and the two required abutments are estimated to cost $200,000 each. The superstructure will be erected at a cost of $0.60 per pound.

1. Which girder design should you choose based on optimum cost?

2. What are the optimum number of piers for this design?

3. What is the optimum cost for this design in dollars?