Yesterday, I was gathering information off the CTC Liaison page as part of updating the highway pages (in progress), when I found a handout about the recesssion of freeway adoption for Route 238 in Hayward and Alameda County. Looking at the attached map, one could see the reasoning. If Route 238 had been completed as freeway as originally intended, it would have been a continuous route from I-680 to I-880, and an interstate number would make sense. Jumping the gun, they got the number assigned through AASHTO for the constructed freeway portion, which since no other even x80 number was available, they assigned as I-238. Then the rest of the routing fell through, and you know the story. The remaining stub of I-238 sticks out like a sore thumb.
But looking at the original map, at least the original intent makes sense.
