More specific information is required. Are you looking for a structure with a minimum construction cost or life cycle cost? There are number of technical and operational parameters which should be defined before recommendation for the most economic selection for your bridge is attempted. Those are:
1) Span length
2) Bridge width
3) Structural depth restrictions
4) Loading (pedestrian, vehicular, railroad
5) Traffic
6) Anticipated duration of service (temporary, permanent)
etc.
7) Local climate
Once the above conditions are identified, it will be easier to provide recommendations.