Springfield Interchange Improvement Project design. In the implementation phase, the discussion addresses detailed design, construction, and commis- sioning. Finally, in the closeout phase, the discussion reflects on overall performance, project status, and project evaluation.
The Inception Phase
The Springfield Interchange is one of the most complex and dangerous interchanges in the United
States (Sipress & Reid, 1999). Situated fifteen miles south of Washington, DC, where the Capital Beltway intersects Interstate Highways I-95 and I-395, the interchange is aptly nicknamed the ‘‘Mixing Bowl,’’ as four of the region’s heaviest streams of traffic rush together in a fury of bobbing and weaving and last- second lane changing in an effort to negotiate the outdated traffic patterns. As many as 375,000 vehicles commute via this route every day, in addition to the constant traffic of I-95, the primary East Coast commercial corridor. The interchange held the distinction of having more accidents than any section of the Beltway or any other area of road in Virginia. Although delays and driver confusion continually reinforced the need to improve the interchange, it was traffic safety issues that finally moved the project off the wish list and onto the drawing board (Behr, 1999).
Although overriding safety concerns drove the project, not everyone was excited about the prospects of a multiyear construction project in the middle of the busiest area of the Washington, DC Beltway. Local businesses were worried about losing customers because drivers would want to avoid the area. Commercial carriers were concerned about the impact the delays would have on their costs. Local residents were distressed that fixing the Mixing Bowl would solve only part