When many military bases were closing, Scott Air Force Base changed its focus to become a joint-use facility. MidAmerica Airport, a civilian facility, opened adjacent to the base in April 1998.

MidAmerica Airport serves both military and civilian needs by providing service for the neighboring Scott Air Force Base and relieving Lambert-St. Louis International Airport.

The civilian runway at MidAmerica Airport is parallel to and 7,000 feet north of the military base runway. The Federal Aviation Administration requires that airports with runways separated by less than 4,300 feet confine air traffic to one runway in severe weather. The separation distance allows the runways at both MidAmerica and Scott Air Force Base to remain operational and avoid delays during inclement weather.

Two taxiway bridges were built to connect these two runways. Hanson provided the following services for the construction of the taxiway bridges between Scott Air Force Base and MidAmerica Airport:

• review of design criteria in preliminary design of taxiway bridges
• final design completion
• technical support during construction
• quality assurance program to keep the costs down and the project on schedule
• The 277-foot-long bridges are each 149 feet wide (a 145-foot center with 2-foot curbs on each side) and will accommodate the giant 1.25 million-pound aircraft of the future.

In addition to the taxiways, decks for nonaircraft traffic were also constructed. These decks minimize vehicular traffic and debris on the taxiway bridges.

Both bridge structures have a post-tensioned box girder superstructure supported by closed abutments and solid piers. They were completed in 1997 for approximately $13 million.