100 years of US routes: 1926-2026

All about single-state US highways

Change page title.

Change the date range.

Check dates against book.

Move banner ads.

Linked pages.

Change sections with white color.

Update migration tracker.

Many of us are familiar with a recurring joke that is often framed as a question, but is actually more of a commentary: "Why are there interstate highways in Hawaii?" After all, at first glance it seems illogical that there would be an interstate which exists only in a single state, despite the fact that its very name indicates that it should cross a state boundary. The same question can be raised with regard to intra-state US highways, i.e. US routes that exist only in a single state. As the logic goes: if the system was devised in order to facilitate inter-state travel, then what would be the point of intra-state US highways? Shouldn't those kinds of roads be classified as state highways?

The short answer is that both classifications (Interstate highways and US highways) were envisioned as a network of routes that would support the majority of travel throughout the country... keeping in mind that some important connecting routes would be entirely within one state. One of the prime examples is Interstate 45, which connects Dallas and Houston, and therefore obviously exists only in Texas. It would be difficult to make a convincing argument that the 4th- and 5th-largest metro areas in the U.S. should not be linked by an interstate highway.

The same rationale applies to the Interstate system's predecessor, the US highway system. The US routes served as the nation's original "inter-state" network, created to aid travelers by providing a unified numbering scheme that was consistent across state lines. Nevertheless, some important connecting routes were located entirely within a single state, so they were included in the US route system.

One can certainly disagree with that rationale and perhaps build a good case against it (as we do in our book). But let it never be said that the US highway system was not intended to include intra-state routes, because that is simply not true.

Intra-state US routes have been around since the very beginning.

If we look at the US highways that were proposed in 1925 by the BPR/AASHO Joint Board, 49 out of 146 routes were single-state (34% of the total). Most of those ended up being included among the 1926 inaugural routes (i.e. those that were officially commissioned). Plus, 20 more were added to that final list: on AASHO's first route log, we find no less than 69 original US routes were intra-state. So out of a total of 188 original routes, 37% were single-state. Included in that number were 12 two-digit US routes (which is somewhat surprising when one considers the fact that two-digit numbers were supposedly reserved for the longer routes in the system). Following is the full list of original 1926 intra-state US routes:

Bold = still intra-state today

* = never signposted

6[w] (PA)

28 (OR)

42 (OH)

48 (CA)

49 (MS)

53 (WI)

68 (KY)

74 (NC)

76 (SC)

92 (FL)

94 (FL)

96 (TX)

102 (MI)

106 (PA)

*109 (NY)

110 (WI)

116 (WY)

118 (WI)

120 (PA)

124 (IL)

129 (GA)

130 (NJ)

131 (MI)

141 (WI)

150 (IN)

151 (WI)

154 (KS)

161 (IA)

166 (KS)

168 (KY)

171 (LA)

181 (TX)

185 (WY)

187 (WY)

190 (LA)

192 (FL)

201 (ME)

209 (PA)

210 (MN)

211 (VA)

213 (MD)

222 (PA)

266 (OK)

*270 (TN)

290 (TX)

295 (WA)

309 (PA)

320 (WY)

330 (IL)

341 (GA)

350 (CO)

370 (TX)

395 (WA)

411 (VA)

420 (WY)

430 (IL)

441 (FL)

470 (NM)

485 (NM)

*511 (TN)

522 (PA)

530 (UT)

550 (CO)

566 (NM)

601 (SC)

611 (PA)

650 (CO)

*711 (PA)

830 (WA)

So single-state US routes have existed from the outset; in fact they comprised a significant percentage of the total. And during the next decade, several additional intra-state routes appeared. Primarily this happened because AASHO continued to commission new single-state US routes. But in a few cases, some existing US routes became single-state routes because they were truncated in such a way that all of their mileage in a neighboring state was eliminated.

During the first decade of the US highway system, AASHO commissioned several new intra-state routes.

On the other hand, during that same timeframe several other intra-state route designations were eliminated. Most often this happened in one of two ways. In several cases, a formerly-single-state route was simply extended into a neighboring state. In several other instances, the intra-state route was decommissioned. What that word means is this: in most cases, it was not that the road itself was removed from the US highway system. Rather, the original route number was eliminated, and the road was simply assigned a different number, because the original route had become a short segment of a longer route. For example, the earliest instance involved the situation with US 102 and US 141. Initially both were single-state US routes (in Michigan and Wisconsin, respectively), but in 1928 the US 141 designation was extended north into Michigan, where it absorbed what had been US 102.

Following is a timeline for the decade 1927-1936, showing all gains and losses of single-state US routes, including a year-by-year running total:

1927

US 6[w]: extended into New York.
US 109: redesignated as US 9-E (a split route of US 9).
US 222: extended into Maryland.
US 227: commissioned as Kentucky intra-state route, not previously a US route.
US 230: truncated, became Pennsylvania intra-state route.
US 401[i]: commissioned as Virginia intra-state route, previously part of US 15.
US 422[e]: commissioned as Pennsylvania intra-state route, previously part of US 120.
US 522: extended into Maryland, absorbing US 622.
US 711: redesignated as US 111 and US 120.
-5 +4, running total 68

1928

US 102: subsumed by extension of US 141.
US 141: extended into Michigan.
US 189[i]: commissioned as Utah intra-state route, not previously a US route.
-2 +1, running total 67

1929

US 270[i]: redesignated as US 70-S (a split route of US 70).
US 511: redesignated as US 11-E (a split route of US 11).
-2, running total 65

1930

US 42: extended into Kentucky.
US 123[i]: commissioned as Kentucky intra-state route, previously US 23.
US 216: commissioned as Wyoming intra-state route, not previously a US route.
US 221: commissioned as North Carolina intra-state route, not previously a US route.
US 377: commissioned as Texas intra-state route, not previously a US route.
US 421: commissioned as North Carolina intra-state route, not previously a US route.
-1 +5, running total 69

1931

US 32: truncated, became Illinois intra-state route.
US 48[i]: subsumed by extension of US 50.
US 58: commissioned as Virginia intra-state route, most of it not previously a US route.
US 175: commissioned as Texas intra-state route, not previously a US route.
US 221: extended into Virginia and South Carolina.
US 260: commissioned as Arizona intra-state route, not previously a US route.
US 280: commissioned as Georgia intra-state route, not previously a US route.
US 366[ii]: commissioned as New Mexico intra-state route, previously US 470.
US 371[i]: commissioned as Minnesota intra-state route, not previously a US route.
US 401[i]: subsumed by new US 58 designation.
US 470: replaced by US 366 designation.
US 485: subsumed by extension of US 64.
US 541: commissioned as Florida intra-state route, not previously a US route.
US 566: subsumed by new US 380 designation.
-6 +8, running total 71

1932

US 68: extended into Ohio.
US 76: extended into Tennessee.
US 178: commissioned as South Carolina intra-state route, not previously a US route.
US 258: commissioned as North Carolina intra-state route, not previously a US route.
US 264: commissioned as North Carolina intra-state route, not previously a US route.
US 411[i]: subsumed by extension of US 421.
US 411[ii]: commissioned as North Carolina intra-state route, not previously a US route.
US 421: extended into Virginia.
US 601: extended into North Carolina.
-5 +4, running total 70

1933

US 32: subsumed by extension of US 34.
US 98: commissioned as Florida intra-state route, not previously a US route.
US 216: extended into South Dakota.
US 319: commissioned as Florida intra-state route, not previously a US route.
US 360: commissioned as Virginia intra-state route to replace part of the rerouted US 60.
US 420: subsumed by extension of US 14.
US 460: commissioned as Virginia intra-state route to replace part of the rerouted US 60.
-3 +4, running total 71

1934

US 53: extended into Minnesota.
US 104: commissioned as New York intra-state route, not previously a US route.
US 116: subsumed by extension of US 14.
US 117[ii]: truncated, became North Carolina intra-state route.
US 122[ii]: commissioned as Pennsylvania intra-state route, some was previously US 120.
US 123[i]: subsumed by extension of US 119.
US 129: extended into Tennessee.
US 150: extended into Kentucky and Illinois.
US 152: commissioned as Indiana intra-state route, not previously a US route.
US 163[i]: commissioned as Iowa intra-state route, previously US 63.
US 168: subsumed by extension of US 150.
US 185: subsumed by extension of US 87.
US 190: extended into Texas.
US 209: extended into New York.
US 281[s]: commissioned as Texas intra-state route, not previously a US route.
US 299: commissioned as California intra-state route, not previously a US route.
US 311: truncated, became North Carolina intra-state route.
US 395: extended into California.
US 399: commissioned as California intra-state route, not previously a US route.
US 411[ii]: subsumed by extension of US 220.
US 430: became state route.
US 450: truncated, became Utah intra-state route.
US 550: extended into New Mexico.
US 601: truncated, became North Carolina intra-state route.
US 650: partly subsumed by new US 285 designation, remainder became state route.
-14 +11, running total 68

1935

US 112: truncated, became Michigan intra-state route.
US 159: commissioned as a Kansas intra-state route, previously part of US 73W.
US 260: extended into New Mexico.
-1 +2, running total 69

1936 (no changes to intra-state US routes)

To recap that first decade: the original system started out with 69 single-state US routes. By 1929 that number dropped to 65, but then climbed to a high of 71 routes, and by the end of 1936 the number was back to 69... so a slight fluctuation, but overall no change to the total number of intra-state routes. So clearly single-state routes were still regarded as an integral part of the US highway system. But in 1937, AASHO decided that mindset needed to change. That year they published a document titled "New Signing Policy on U.S. Routes". The whole article is an interesting read, but one particular excerpt is relevant to the topic of this page:

Starting in 1937, AASHO encouraged the states to eliminate their intra-state routes.

The reasons why AASHO decided to change its position on single-state US routes are interesting. During those early years many civic-minded people believed that one important key to economic prosperity was to have their town served by a US route (similar to the previous mindset about being located on a railroad, or the current mindset about the importance of being connected to the Interstate highway system). But when looking at some of the additions to the system listed above, it seems apparent that some of the new routes were only of regional importance, and did not quite belong with the most important highways in the national network. By allowing single-state US routes, AASHO had been keeping the barrier-to-entry too low (more on this topic in our book).

AASHO had clearly reached a point where they believed a change was necessary, and they began to emphasize the fact that state highways were perfectly capable of facilitating intra-state connections. This had an immediate impact: within just three years, the number of single-state US routes was quickly reduced by 16 (and after that the count continued to drop, although much more gradually). Following is a continuation of the timeline for the next three decades (from 1937 through 1969). By the end of this period, the overall number of intra-state routes had been reduced by about half:

1937

US 118: subsumed by extension of US 151.
US 151: extended into Iowa.
US 161: subsumed by extensions of US 151 and US 218.
US 163[i]: became state route.
US 178: extended into North Carolina.
US 319: extended into Georgia.
-6, running total 63

1938

US 110: became state route.
US 124: became state route.
US 152: reverted to state route.
US 189[i]: became state route.
US 281[s]: connected with US 281[n].
US 366[ii]: partially subsumed by extension of US 66, remainder became state route.
US 450: subsumed by extension of US 160.
US 530: subsumed by extension of US 189.
-8, running total 55

1939

US 96[i]: subsumed by extension of US 59.
US 96[ii]: commissioned as Texas intra-state route, previously US 59.
US 320: became state route (later part of extended US 26).
US 370: subsumed by extension of US 287.
-3 +1, running total 53

1940

US 158: truncated, became North Carolina intra-state route.
US 258: extended into Virginia.
-1 +1, running total 53

1941

US 330: redesignated as US 30-A.
-1, running total 52

1942

US 159: extended into Missouri.
-1, running total 51

1944

US 166: extended into Missouri.
-1, running total 50

1946

US 460: extended into Missouri.
-1, running total 49

1948

US 441: extended into Georgia.
-1, running total 48

1949

US 94: subsumed by extension of US 41.
-1, running total 47

1950

US 601: extended into South Carolina.
-1, running total 46

1951

US 28: partly subsumed by extension of US 26, remainder became US 126.
US 126: commissioned as Oregon intra-state route, previously US 28.
US 541: subsumed by relocation of US 41 (the old alignment of which was replaced by extension of US 301).
-2 +1, running total 45

1952

US 46: truncated, became New Jersey intra-state route.
US 611: extended into New Jersey.
-1 +1, running total 45

1953

US 280: extended into Alabama.
-1, running total 44

1954

US 98: extended into Mississippi. (From 1951-1954, US 98 had been the longest-ever single-state US route, at about 655 miles in length.)
-1, running total 43

1956

US 156: commissioned as Kansas intra-state route, previously US 50-N.
+1, running total 44

1959

US 312: commissioned as Montana intra-state route, previously US 12.
+1, running total 45

1961

US 112: subsumed by reroute of US 12.
-1, running total 44

1962

US 122[ii]: became state routes.
-1, running total 43

1963

US 49: extended into Arkansas.
US 131: extended into Indiana.
US 299: became state route.
US 399: became state route.
-4, running total 39

1964

US 611: truncated, became Pennsylvania intra-state route.
+1, running total 40

1965

US 230: became state route.
-1, running total 39

1966

US 120: became state route.
-1, running total 38

1967

US 295: became state route.
US 309: became state route.
US 830: became state route.
-3, running total 35

1968

US 131: truncated, became Michigan intra-state route.
US 377: extended into Oklahoma.
-1 +1, running total 35

1969

US 99: truncated, became Oregon intra-state route.
US 195: truncated, became Washington intra-state route.
US 210: became state route.
-1 +2, running total 36

Even after 1937, a few new intra-state routes were still created.

Despite AASHO's 1937 edict, a few additional intra-state US routes were still created during the 1940s through the '60s -- ten, to be exact. It should be noted that only four of them were newly-commissioned, whereas the other six simply became single-state routes due to truncations or reroutings (US 46, 99, 131, 158, 195, 611). But still, why did AASHO allow the four new intra-state routes? Here is my take: the verbiage of the 1937 document specified "...no new US route..." (emphasis mine).

In all four of those instances, the new numbers were applied to routes that were not new to the system. Rather, those corridors had already been accepted into the US highway system; they simply needed new numbers because their former numbers had been rerouted or eliminated:

US 96 was commissioned along the former US 59,
US 126 was commissioned along the former US 28,
US 156 was commissioned along the former US 50N,
US 312 was commissioned along the former US 12.

In other words, AASHO was acting in accordance with what we refer to in our book as "the perpetuity principle". Exceptions notwithstanding, overall the number of intra-state US routes steadily declined after 1937, which suggests that for many years AASHO continued to push the states to eliminate them. In the minutes of their June 1970 meeting, they even included a list of single-state routes that were still in existence at the time:

There are several things (both on that list and omitted from that list) that are worthy of comment. We will begin by noting a typo: there has never been a US 212 in Maryland. We can be quite certain they meant to type "213". Also, two of the routes on that list should not have been included. At their previous meeting (Oct. 1969) AASHO had just granted approval for Minnesota to decommission US 210. And one year before that (June 1968), they approved an extension of the US 377 designation into Oklahoma, so it was no longer a single-state route. So that leaves 18 routes, but it would be an error to assume that list was complete... because we should also note several routes that were overlooked. At the time, there were not 18, but actually 36 single-state US highways -- twice as many as were listed. 18 additional routes should have been included, and the full list should have been as follows:

US 46 - New Jersey (since 1952)
US 58 - Virginia (since 1966)
US 74 - North Carolina (since 1926)
US 92 - Florida (since 1926)
US 96 - Texas (since 1939)
US 99 - Oregon (since 1969)
US 104 - New York (since 1934)
US 106 - Pennsylvania (since 1926)
US 117 - North Carolina (since 1934)
US 126 - Oregon (since 1951)
US 130 - New Jersey (since 1926)
US 131 - Michigan (since 1968)

US 154 - Kansas (since 1926)
US 156 - Kansas (since 1956)
US 158 - North Carolina (since 1940)
US 171 - Louisiana (since 1926)
US 175 - Texas (since 1931)
US 181 - Texas (since 1926)
US 187 - Wyoming (since 1926)
US 192 - Florida (since 1926)
US 195 - Washington (since 1969)
US 201 - Maine (since 1926)
US 211 - Virginia (since 1926)
US 213 - Maryland (since 1926)

US 227 - Kentucky (since 1928)
US 264 - North Carolina (since 1932)
US 266 - Oklahoma (since 1926)
US 290 - Texas (since 1926)
US 311 - North Carolina (since 1934)
US 312 - Montana (since 1959)
US 341 - Georgia (since 1926)
US 350 - Colorado (since 1926)
US 360 - Virginia (since 1933)
US 371[i] - Minnesota (since 1932)
US 422[e] - Pennsylvania (since 1927)
US 611 - Pennsylvania (since 1964)

That oversight was probably embarrassing for AASHO, and the following year they issued a corrected list (as we will see below). However, there was also something utterly baffling: less than five months after AASHO issued their original 1970 list, they turned around and approved the creation of intra-state US 57 in Texas, along a route that was not previously included in the US highway system. I have outlined the reasons for that on the US 57 page, but regardless of the rationale, I imagine AASHO lost a lot of credibility by approving US 57, and it would be understandable if that was the reason several state DOTs felt it was not worth the bother to take any further action in response to AASHO's latest request to eliminate intra-state US routes. Georgia was perhaps the first of the state DOTs to push back against AASHO's suggestions. The following excerpt from their Jan. 1971 letter to AASHO contained one good point and one dubious argument:

"1937" was a reference to the year AASHO first suggested that single-state US routes should be eliminated, and Georgia was highlighting the fact that US 341 was commissioned prior to that. But their suggestion that the Brunswick-Barnesville corridor was somehow deserving of special status was shaky at best.

AASHO's final attempt to eliminate intra-state routes was in 1971.

In July 1971 AASHO sent a revised list to the state DOTs. This one was greatly improved, as it contained 32 single-state routes. US 104 and US 126 were no longer included, because by then NY and OR had already changed them to state routes. There were only two intra-state routes notably absent from the 1971 list. One was US 74. And the other was US 57... which AASHO had just approved eight months earlier. That must have come across as quite disingenuous. And so must have AASHO's July 1971 letter, which emphasized their position even more forcefully, going so far as to call intra-state US routes "illegal":

Some state DOTs responded with equal fervor against eliminating intra-state routes. In the following excerpt from Virginia DOT's letter, the "three long sections" refers to their three single-state routes (US 58, US 211, and US 360):

Georgia weighed in again, but did not make any additional points beyond what was said in their previous letter:

Oklahoma said they did not contemplate taking any immediate action on US 266, but at the same time they made an interesting comment that they "expected" to delete it at some time in the future:

Utah was a little more diplomatic, noting that their joint proposal with Wyoming to extend US 163 northward (which AASHO had just recently disapproved) had the potential to not only eliminate intra-state US 187 but also to make the short US 163 a more legitimate US route:

Washington did not seem to have a strong opinion either way, but they simply noted the possibility that US 195 was about to lose its intra-state status:

US 195 was indeed extended into Idaho a few years later. But, with the exception of US 187, all of the other US routes mentioned in those letters remain intra-state highways to this day. And with regard to the others: now that we have a complete list of the single-state US routes that existed at the time, we can determine that within three years, the overall count had been reduced by seven. And during the 1980s eight additional intra-state routes would be eliminated, but beyond that the effort completely stalled. Following are the remaining changes to single-state US routes, from 1970 to present:

1970

US 57: commissioned as a Texas intra-state route, not previously a US route. This was the last single-state US route to be commissioned.
US 126: became state route.
US 441[n]: separated from US 441[s].
-1 +2, running total 37

1971

US 99: became state route.
US 104: became state route.
US 106: became state routes.
US 131: extended into Indiana.
US 213: partly subsumed by US 301, remainder became state route.
US 371[i]: became state route.
US 611: became state route.
-7, running total 30

1972

US 227: became state route.
-1, running total 29

1973

(AASHO became AASHTO)

1975

US 195: extended into Idaho.
-1, running total 28

1979

US 154: became state route.
US 156: became state route.
US 312: subsumed by extension of US 212.
-3, running total 25

1981

US 187: subsumed by extension of US 191.
-1, running total 24

1986

US 74: extended into Tennessee.
-1, running total 23

1996

US 58 extended into Tennessee.
-1, running total 22

2012

US 311: extended into Virginia.
-1, running total 21

Currently the US route system still includes 21 intra-state routes.

Of those 21, 11 were among the inaugural routes of 1926 (shown in bold below). Here is the current list of single-state US routes (with some notes), sorted in order of approx. mileage:

US 266 (43.0 mi. in OK)
US 211 (59.0 mi. in VA) Historically extended into DC.
US 441[n] (69.2 mi. in TN) Was connected to 441[s] until 1970.
US 350 (72.8 mi. in CO)
US 192 (74.6 mi. in FL) Can’t use the same excuse as US 92, because it doesn’t even make it all the way across the peninsula.
US 46 (74.9 mi. in NJ) Historically went a fraction of a mile into PA; see this blog post.
US 422[e] (82.9 mi. in PA) Was never connected to 422[w].
US 130 (83.2 mi. in NJ) Might make a good northern extension of US 301.
US 57 (98.4 mi. in TX) Connects to international port-of-entry and Mexico hwy. 57.
US 175 (109.9 mi. in TX) Could become an extension of US 75; current endpoints are separated by only two miles.
US 117 (113.5 mi. in NC)
US 181 (135.9 mi. in TX)
US 201 (157.3 mi. in ME) Connects to international port-of-entry and Quebec hwy. 173.
US 96 (165 mi. in TX) See this blog post.
US 171 (178 mi. in LA)
US 92 (182 mi. in FL) East-west route that spans the entire breadth of peninsula.
US 264 (213 mi. in NC)
US 341 (224 mi. in GA)
US 360 (225 mi. in VA) Should be extended along US 311 to Winston-Salem; see this blog post.
US 290 (274 mi. in TX)
US 158 (346 mi. in NC) Historically routed into VA. Over 300 miles long, so does not violate 1937 AASHO guidelines.

Which state currently has the most intra-state routes? And what about historically?

An examination of the list above reveals that five of the 21 current single-state routes are in Texas. As it turns out, Texas has had a minimum of four intra-states ever since the US route system was inaugurated in 1926. And during the 1930s it actually claimed six. Maybe that should not be surprising, given the size of Texas. However, six is not the most that any state has ever had.

Way up at the top of this page, the 1926 list shows that Pennsylvania had nine intra-states at the time... although that is a bit misleading, because by the time Pennsylvania actually began signposting their US routes in 1928, they were down to seven. Still, there is no question that Pennsylvania was very fond of their intra-states for a long time: they held on to seven of them all the way until 1963, a span of 35 years. On the other hand, once they decided to start eliminating their intra-states, they were quick about it: within a decade, all but one were gone.

For a three-year period during the mid-1930s, Florida also claimed seven signposted intra-states.

North Carolina had six intra-states from 1935-1949. And they had at least five from 1934-1982, a span of 48 years.

Both Wisconsin and Wyoming started out with five each in 1926 (tied for second behind Pennsylvania). Wyoming even increased to six during the early 1930s. But after that both states began to eliminate them quickly: by 1938 Wyoming had only one intra-state remaining, and Wisconsin had none.

Should the surviving intra-state routes be eliminated?

People who have put some thought into single-state US routes are generally divided on how they should be handled going forward. Some are of the opinion that they should be allowed to remain, for various reasons (e.g. they have been in the system since the beginning; important connecting routes should not be required to cross a state line; they don't do any harm so it's not worth the hassle and expense of changing them; etc.) Others insist that intra-state US routes are not appropriate, and that they should be replaced with state highway designations.

I can see both sides, but I also think the point is moot, because it appears AASHO/AASHTO has not made any effort to enforce their guideline since the 1970s. So I believe the 21 remaining single-state routes that survived the earlier purges are "safe" from that organization now. I seriously doubt AASHTO will ever issue another edict about this -- they have long since stopped concerning themselves with that kind of thing. Of course it is always possible that an individual state DOT may have a compelling reason to convert an intra-state US route to a state route, but keep in mind these routes have been around for decades. Any states that wanted to systematically decommission their intra-state US routes already did so a long time ago (the last state to do this was Kansas, back in 1979).

There are also several defacto intra-state routes.

For those who think the state DOTs should decommission their intra-states, I think it is only fair to also take a position on what I call "stealth violators". These are US routes that often escape scrutiny because they do enter a second state... but they do so only for a very short distance, so in a practical sense they are defacto single-state routes. What should be the minimum mileage in a second state for a highway to be considered a "legitimate" US route? The answer is open to debate, but the list below includes those with 15 miles or less. In my opinion, some of the following stealth violators are even worse than some of the actual violators listed above. These are sorted in order of total mileage in the second state:

US 206: 129.8 mi. in NJ, 0.4 mi. in PA.
US 195: 93.2 mi. in WA, 0.5 mi. in ID.
US 166: 163 mi. in KS, 0.6 mi. in MO.
US 58: 508 mi. in VA, 0.7 mi. in TN. (although this is well over the 300-mile threshold)
US 223: 46.3 mi. in MI, 0.8 mi. in OH. (90% of US 223 is in a single county, if one ignores the pointless overlap with US 23)
US 131: 270 mi. in MI, 0.8 mi. in IN.
US 197: 60.5 mi. in OR, 2.8 mi. in WA.
US 177: 229.5 mi. in OK, 3.5 mi. in KS.
US 222: 91.4 mi. in PA, 3.6 mi. in MD.
US 521: 173.6 mi. in SC, 3.7 mi. in NC.
US 730: 35.5 mi. in OR, 6 mi. in WA. (currently the shortest route in the entire US highway system)
US 178: 234 mi. in SC, 6.5 mi. in NC.
US 311: 57.9 mi. in NC, 7.5 mi. in VA. (see this blog post)
US 138: 59.9 mi. in CO, 11.4 mi. in NE.
US 48: 142.8 mi. in WV, 14.2 mi. in VA.
US 400: 467 mi. in KS, 14.7 mi. in CO, 0.6 mi. in MO. (see this blog post)

Research and/or image credits: Nathan Edgars; Mike Roberson; Dale Sanderson; Michael Summa

Page originally created 2020;last updated Sep. 07, 2025.

Page updated

Google Sites

Report abuse