I didn't do this when it was first found.
Auburn, WA
Along Primary Interstates: I-5
Along US Numbered Highways (<=5mi): None
Along Auxiliary Interstates: None
Along State Routes: WA-18, WA-167
I-5
From: Centralia, WA - 65.4 miles
To: Lynnwood, WA (WA-167, I-405) - 42.2 miles
Diversion: 4 miles
From: Vancouver, WA - 141.2 miles
To: Arlington, WA - 70.1 miles
To: Bellevue,WA (WA-167, I-405) - 25.5 miles
From: Aberdeen, WA (US-12, WA-12, US-101, I-5, WA-512, WA-167) - 90.8 miles
To: North Bend, WA (Construction) (WA-18, I-90) - 35.9 miles
Seems like a pretty handy location for N-S, E-W and S-E travel.
A bit a diversion from I-5, but not too bad, and split a 103.6 mile gap from Centralia, WA to Lynwood, WA, so that the only gaps of 100 miles or more along I-5 are in the Northern California to Oregon connection (Sacramento, CA to Corning, CA to Mt. Shasta, CA to Grants Pass, OR to Springfield OR; Williams, CA will split Sacramento, CA to Corning, CA).