David Evans and Associates served as the project's prime engineer and lead designer. Much of the Airport MAX used public right-of-way owned either by the Oregon Department of Transportation, the Port, or TriMet. This avoided displacing any property owners and contributed to the line's rapid completion. Overall, the extension limited its impact to the elimination of 20 parking spaces at Gateway Transit Center and several others along Airport Way. Bechtel began construction in June 1999 on a segment next to I-205 near the Columbia Slough. Bridgework over the freeway commenced the following December. To minimize lane closures, workers used a cast-in-place concrete pouring method to extend the bridges' spans in increments. Work progressed quickly along the freeway segment due to the already-built I-205 Transitway, which accommodated a tunnel from Gateway Transit Center to the freeway median in anticipation of a busway that never materialized.