Interstate 105 connects Oregon Route 99 outside Downtown Eugene with I-5 and Oregon Route 126 (Eugene-Springfield Highway) at the Springfield city line. Following an L-shaped course, I-105 leads north from ramps with the couplets of 6th/7th Avenues and Jefferson/Washington Streets, where OR 99, OR 126 and OR 126 Business converge. The Washington-Jefferson Bridge spans the Willamette River into the trumpet interchange (Exit 1) with Delta Highway. I-105/OR 126 (Pacific-Willamette Highway) turn east from there to Coburg Road and I-5.
Construction for Interstate 105 in Eugene, including the Washington-Jefferson Bridge started in the early 1960s. The freeway fully opened to traffic in 1970 without controversy, unlike the other proposed Interstate spurs in Oregon that were never built (I-305 and I-505).1
Costing $15 million, road construction (project #10349) in 2005 expanded Interstate 105 with auxiliary lanes in both directions between mileposts 0.89 and 3.95.2