2-lane interstates

[NE2]

All the way to 151: http://mapper.acme.com/?ll=39.24194,-76.46579&z=16&t=O

Trivia: the part between I-95 (northeast) and I-97 was never officially added to the Interstate system. Neither was I-895 south of I-695.
http://www.marylandroads.com/Location/2009_BALTIMORE.pdf http://www.marylandroads.com/Location/2009_ARUNDEL.pdf http://www.fhwa.dot.gov/planning/nhs/maps/md/baltimore_md.pdf
Note that MDSHA calls the former MD 695, but the latter I-895 (on Baltimore County page 45 you can see the functional classification change from freeway to Interstate).

[MDOTFanFB]

Here's some Michigan examples:

I-75 between both peninsulas of Michigan: Mackinac Bridge Actually, according to Google Maps, it is four lanes across the bridge.

I-69 and I-94 at the Canadian border before the Blue Water Bridge was twinned in the mid-90's.

Removed the quote, NG beat me.

[agentsteel53]

I thought the Mackinac was a very narrow four-lane with no shoulders?

[nexus73]

I-80N, now I-84, had a Super 2 section between Ontario and Baker when it was first built.  I believe that section of freeway went to 4-lane in the later 1970's.  Maybe one of the other posters from Oregon will know more of the details.  It was the only Super 2 Interstate section we had in Oregon AFAIK.

Rick

[xonhulu]

I-80N, now I-84, had a Super 2 section between Ontario and Baker when it was first built.  I believe that section of freeway went to 4-lane in the later 1970's.  Maybe one of the other posters from Oregon will know more of the details.  It was the only Super 2 Interstate section we had in Oregon AFAIK.

Rick

Probably correct.  Some sections of then I-80N were originally left as 2 lanes, and were upgraded to 4 lanes between 1966 and 1980.  See the following link for an ODOT document on the history of Oregon's Interstates:

http://www.scribd.com/doc/331938/The-History-of-Oregons-Interstate-Highways

[InterstateNG]

I thought the Mackinac was a very narrow four-lane with no shoulders?

It is.

[nexus73]

Thanks for the link Xonhulu!

Rick

[hbelkins]

I thought the Mackinac was a very narrow four-lane with no shoulders?

http://www.millenniumhwy.net/videos/Mackinac_Bridge.mp4