Numbers that are used for several important state routes in the US

[hotdogPi]

Keep in mind that lower numbers are expected to have more important routes with that number, so higher numbers have a lower threshold for inclusion.

28: VA, PA, NY, and MA/NH.

32: CT/MA/NH, NY, MD, OH, and WI.

37: CA, VA, IN, and RI.

55: ID, NJ, CA, and MN.

60: CA, FL, and IA/MN.

66: OK, IN, PA, and CT.

73: CA, OH, and NJ/PA.

99: CA, OR, WA, and TX.

200: ID/MT/ND/MN and MD.

202: AZ and FL.

288: VA and TX.

[GaryV]

I'm not sure what your criteria are, but you can add MI to 28, 37, 55 and 66.

[hotdogPi]

I'm not sure what your criteria are, but you can add MI to 28, 37, 55 and 66.

It's a bit subjective.

[sparker]

I would definitely add 58 as applied in both CA and OR; both are interregional arterials that carry both commercial and recreational traffic.  Actually, there are a few similarities:  at their western ends (at least with the commercially viable section of the CA corridor) they convey their traffic to a N-S arterial near the south end of the state's main agricultural valley, and each is paralleled by a major ex-Southern Pacific main rail line (now part of UP). 

[bassoon1986]

LA could also be added to 28 as well. Major east-west corridor in central Louisiana, and the only way to reach highways into Mississippi for a large portion of Louisiana.


iPhone

[roadman65]

1- LA, DE, and GA (US 27).

[hotdogPi]

1- LA, DE, and GA (US 27).

Even with CA and IL added to the list, five states probably isn't enough for a number that low, especially since one shadows a US route.

[GaryV]

Add M-1. It's not very long, but it's important and historical.

[mrcmc888]

You can add TN-66 to that list; it's the main way to get from I-40 through Sevierville to US-441/321 at Pigeon Forge and then to the Smokies.

72 seems like a pretty important number as well.  You have DE-72 which is an important connector of suburban towns in Newcastle County, DE, SC-72 which runs almost the entire length of the state in the Upstate area, connected to GA-72 which links Athens to the SC-72 corridor, TN-72 which is a heavily-traveled back way from Kingston to Blount County, TX-72 which links farming communities in South Texas, and CA-72, which may be short but it is a major thoroughfare in Los Angeles.

[GaryV]

You can add TN-66 to that list; it's the main way to get from I-40 through Sevierville to US-441/321 at Pigeon Forge and then to the Smokies.

72 seems like a pretty important number as well.  You have DE-72 which is an important connector of suburban towns in Newcastle County, DE, SC-72 which runs almost the entire length of the state in the Upstate area, connected to GA-72 which links Athens to the SC-72 corridor, TN-72 which is a heavily-traveled back way from Kingston to Blount County, TX-72 which links farming communities in South Texas, and CA-72, which may be short but it is a major thoroughfare in Los Angeles.

Add M-72 - it's a cross-the-fingers route from Lake Michigan to Lake Huron, going through many tourist spots.

[sparker]

You can add TN-66 to that list; it's the main way to get from I-40 through Sevierville to US-441/321 at Pigeon Forge and then to the Smokies.

72 seems like a pretty important number as well.  You have DE-72 which is an important connector of suburban towns in Newcastle County, DE, SC-72 which runs almost the entire length of the state in the Upstate area, connected to GA-72 which links Athens to the SC-72 corridor, TN-72 which is a heavily-traveled back way from Kingston to Blount County, TX-72 which links farming communities in South Texas, and CA-72, which may be short but it is a major thoroughfare in Los Angeles.

Don't know if CA 72 is all that important today; it was the alignment of the old US 101 pre-1956, but in the 62 years since has been truncated one section at a time and relinquished to the cities through which it travels; all that's left is a short stretch between I-605 and CA 39 along Whittier Blvd, with only sporadic signage (as of 2012, the last time I was in the area). 

[Scott5114]

KS and OK 99 are both border-to-border routes, so you can add them in on the 99 line.

[US 89]

Add in Utah for 73. A few segments of SR-73 now have enough traffic that they’ll be upgraded to a freeway within 10 years.

KS and OK 99 are both border-to-border routes, so you can add them in on the 99 line.

I’ve always figured that OK/KS/NE 99 plus NE 50 would make a good extension of US 377.

[TheHighwayMan3561]

100 - MN, WI

[Eth]

400 is important in both Georgia and Florida, though admittedly the latter is mostly hidden under I-4.

[74/171FAN]

72 seems like a pretty important number as well.  You have DE-72 which is an important connector of suburban towns in Newcastle County, DE, SC-72 which runs almost the entire length of the state in the Upstate area, connected to GA-72 which links Athens to the SC-72 corridor, TN-72 which is a heavily-traveled back way from Kingston to Blount County, TX-72 which links farming communities in South Texas, and CA-72, which may be short but it is a major thoroughfare in Los Angeles.

I'd include PA 72 as it links Lancaster to Lebanon and Lebanon to I-81 near the west end of I-78.  PA 72 also has an interchange with I-76/PA Turnpike (Exit 266) near Cornwall.

60: CA, FL, and IA/MN.

PA 60 would have made this list a decade ago.  (and maybe still would make this list if it had stayed on I-376 to follow what was PA 60 BUS and now I-376 BUS)

[jeffandnicole]

1- LA, DE, and GA (US 27).

Even with CA and IL added to the list, five states probably isn't enough for a number that low, especially since one shadows a US route.

That's like saying I-95, I-80 and US 101 aren't important because they're high numbers.

Quite a number of states - in fact, over 25% of the states in the country - can't use 1 because of US 1.

[webny99]

1- LA, DE, and GA (US 27).

Even with CA and IL added to the list, five states probably isn't enough for a number that low, especially since one shadows a US route.

That's like saying I-95, I-80 and US 101 aren't important because they're high numbers.
Quite a number of states - in fact, over 25% of the states in the country - can't use 1 because of US 1.

His point is that lower numbers are far more commonly used overall. Because there's higher usage of low numbers, then there needs to be a higher number of states with a significant SR of a low number to make it noteworthy.

If there were a bunch of states with an important SR 573, for example, that would be a lot more noteworthy than the same situation for a two-digit (or one-digit) number.

[mrose]

92 - seems to be a major east/west in Nebraska, Iowa, and into Illinois, and all three are continuous with each other.

[sparker]

The number 60 seems to pop up in several states as a major corridor; there's the cross-state FL 60, the MSR (IA/MN) 60 that provides a large portion of the major connection between the Twin Cities and points to the southwest, and, of course, CA 60, which is likely the most heavily-traveled version of those state routes (albeit its status is just a bit tarnished by the fact that the number is a renumbering of the independent CA section of the former US route of the same number).  Also, OH 60 does traverse the state south-to-north -- although it's only a major regional corridor in its southern reaches; WI 60 crosses the entire state, but only the section following the Wisconsin River has any importance.  Finally, M-60 in MI is a major regional connector within the state, but it's overshadowed by I-94 to the north and US 12 (formerly 112) to the south. 

[webny99]

^ NY 60 might contribute to your case for 60. It's not in the top ten or probably even twenty most important state routes statewide, but it has some regional significance.