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Author Topic: Same number concurrencies or highways meeting  (Read 7134 times)


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Re: Same number concurrencies or highways meeting
« Reply #75 on: March 16, 2019, 05:10:27 PM »

If you include situations where a road continues under the same number but in a different class, this is not terribly uncommon.

In California, I-15, I-110, I-210, and I-238 all continue under the same number but as state routes instead of Interstates.

In Pennsylvania, US 222 continues as PA 222 in Allentown. I was also going to suggest I-378 as a historical example, but I believe the non-freeway portion south of the Lehigh River wasn’t designated as PA 378 until the Interstate designation was removed.

In California I-710 was going to continue as CA-710 if the freeway was going to expand from Alhambra to Pasadena at the CA-134@ I-210.

Also there were old maps showing that there was going to be a CA-380 west of I-380@ I-280 interchange in San Bruno.


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    • my Hot Springs and Highways pages
Re: Same number concurrencies or highways meeting
« Reply #76 on: March 16, 2019, 05:34:22 PM »

There are also lollipop-shaped routes that intersect themselves. Like QC 132, which loops around the Gaspe Peninsula and back to intersect itself near Mont-Joli.

« Last Edit: March 16, 2019, 05:52:20 PM by oscar »
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Re: Same number concurrencies or highways meeting
« Reply #77 on: March 16, 2019, 05:46:58 PM »

So, you can't have a US highway and interstate in the same state.
Is this is a serious rule?

Yes, and until the 74/74 and 41/41 abominations came along, to the best of my knowledge Illinois had the only exception, with the reasoning being that the two routes were so far apart that no one would get them confused.

No such rule in Michigan.  We currently have I- and M-69, 75, 94, and 96; US-10 and M-10; US-24 and M-24; and US-45 and M-45.  Used to be even more.  Michigan actually originally made a point of assigning nearby M and US routes the same number.  Thus we used to have US-112 and M-112 running parallel only about a mile or so apart between Detroit and Ypsilanti, M-131's southern terminus used to be at US-131's northern terminus, and similar with 24 and 25.

Most of Michigan's current number duplications are far part enough that there's no confusion, although I-96/M-96 aren't all that far apart, nor are I-75/M-75 and US-24/M-24.  The latter have interchanges with I-75 only 12 miles apart and there are signs on I-75 to remind motorists of the distinction.

« Last Edit: March 16, 2019, 05:49:30 PM by wanderer2575 »


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