These dual structures carry Interstate 55 over Lake Springfield on the south edge of Springfield in Sangamon County . The old structures consisted on numerous short spans which impeded boat traffic, obstructed views of the property owners and presented maintenance problems for the department. Working with the City of Springfield and lake homeowners, it was agreed to build a shorter bridge with longer spans. This allowed freer movement of boats and provided a more open view for homeowners. Modern highway lighting was provided to safely light the roadway, but antique style street lights were also installed to enhance this gateway into Springfield . During construction a system of buoys was placed to direct boat traffic away from the work area and provide safe passage through the bridge.