Route Continuity and Legibility

[Ned Weasel]

I was thinking recently about Interstate routes that exist in scattered segments, sometimes within the same state (I-49, 69, 73, and 74, most notably), and I realized a similarity between this phenomenon and US routes that have unsigned segments.  On paper, they're two different things, but the end-user experience is almost identical: the route is impossible to follow without prior knowledge of where the connections occur.  Personally, I would like to see both issues remedied, but I understand many DOTs are reluctant to use signage that could be perceived as message loading.

My question is this:  How do DOTs aim toward legibility within highway routes under the existing and ongoing paradigm of route discontinuity?  Does the general public typically accept these situations as separate iterations of a recurring identifier, or does confusion typically occur when communicating travel directions that use discontinuous route identifiers?  One might read this as an argument in favor of the named freeway, but the predominant trend in signage and identification has moved away from names in favor of route numbers.  One usually hears the northern portion of the San Diego Freeway referred to as "The 405," and signs for the I-294 Tollway often omit the name "Tri-State."

Are we simply experiencing a haphazard, ad-hoc form of communication, or is a greater guiding principle at play?

[hbelkins]

What you're mentioning regarding interstates is basically a smaller-scale repeat of how things were back in the 1960s and well into the 70s, when the interstates were being completed in portions and the surface route links between the open segments were primarily signed as "To I-xx."

I-49 is coming together faster than the other routes, but I'm not familiar enough with it to know if the gaps are signed with "To..." signs or not. Ditto I-73.

For I-69, the route is currently so disconnected that it's not really being used as any kind of thoroughfare. You have disconnected segments in Texas and Mississippi that don't really link to anything. I think Kentucky and Indiana would do well to post "To I-69" or "TEMP I-69" signs along US 41 between Henderson and Evansville.

As for I-74, it will always exist as two separate routes, like I-88 in New York and Illinois. Anything West Virginia builds is going to be a surface expressway that will be signed as US 52, and Ohio won't build a link between Huntington and Cincinnati as long as the AA Highway, US 23/OH 32 and US 35/OH 32 corridors continue to serve their purpose.

If you're referring to US highways, that seems to be a situation more commonly encountered out west, where some routes disappear under an interstate (US 85/87 is the one I'm thinking of).

Some states are terrible about not signing concurrencies of state routes. Arkansas is the one that jumps to my mind.

[Max Rockatansky]

Personally I'd rather have a multiplex signed if it exists.  US 17 in Georgia was hard to follow because there is no multiplex signage that reassures you that I-95 will take you where your intended target is until you reach a junction.  In places like California at least the multiplexed route usually is co-signed with a smaller reassurance shield on Interstates and other types of highways. 

Regarding Intestate continuity signage or temporary signage really I don't see it as practical unless the gap between limited access segments is short. 

[sprjus4]

Ditto I-73.

I-73 currently only exists in one continuous 101 mile segment through central North Carolina. There's no gaps that presently exist as far as I-73 signed roadways go.

I think Kentucky and Indiana would do well to post "To I-69" or "TEMP I-69" signs along US 41 between Henderson and Evansville.

Agreed. I-85 had such signage between High Point and Lexington, NC when it was still utilizing the outdated 50s expressway portion before the interstate highway was constructed east of there in the 80s.

As for I-74, it will always exist as two separate routes, like I-88 in New York and Illinois. Anything West Virginia builds is going to be a surface expressway that will be signed as US 52, and Ohio won't build a link between Huntington and Cincinnati as long as the AA Highway, US 23/OH 32 and US 35/OH 32 corridors continue to serve their purpose.

IMO, I-74 needs to be eliminated in North Carolina all together. The portion between I-77 and I-73 could be signed as an I-x73, I-x77, or a short 2di as it would be close to 90 miles long. The piece from Rockingham to Wilmington could be incorporated into a future designation for the US-74 corridor between I-26 southeast of Asheville and Wilmington via Charlotte. This has been discussed as an official proposal in the past, and would be a logical addition, and would eliminate the need for I-74 between Rockingham and Wilmington, and ultimately I-74 all together south of Cincinnati.

[Ned Weasel]

Ditto I-73.

I-73 currently only exists in one continuous 101 mile segment through central North Carolina. There's no gaps that presently exist as far as I-73 signed roadways go.

Oops, my bad.

[Eth]

Personally I'd rather have a multiplex signed if it exists.  US 17 in Georgia was hard to follow because there is no multiplex signage that reassures you that I-95 will take you where your intended target is until you reach a junction.  In places like California at least the multiplexed route usually is co-signed with a smaller reassurance shield on Interstates and other types of highways.

US 17 doesn't follow I-95 in Georgia. Did you mean I-16 or I-516?

[TheGrassGuy]

Colorado literally doesn't sign any of its multiplexes with interstates.

[GaryV]

Does it really matter?

If you know how to read maps, you'll notice that US-xx joins I-yy at one place and then exits on its own at another.

If you don't know how to read maps, the GoogleQuest lady will tell you where to go.

[sprjus4]

Personally I'd rather have a multiplex signed if it exists.  US 17 in Georgia was hard to follow because there is no multiplex signage that reassures you that I-95 will take you where your intended target is until you reach a junction.  In places like California at least the multiplexed route usually is co-signed with a smaller reassurance shield on Interstates and other types of highways.

US 17 doesn't follow I-95 in Georgia. Did you mean I-16 or I-516?

I'd assume I-16, because I-516 has US-17 reassurance shields, though I-16 does not, it's strictly "I-16".

Most states will post reassurance shields on multiplexes.

I-85 south of Lexington, NC is multiplexed with 3 US routes for example, and all are signed.

[usends]

Colorado literally doesn't sign any of its multiplexes with interstates.

Colorado literally does sign a few of its interstate overlaps.  But those are the exceptions, not the rule.

[Flint1979]

US-23 is well signed along it's 73 mile multiplex with I-75 in Michigan. Michigan also signs the multiplex with I-75 and M-55.  Statewide they do a good job signing multiplexes.