For example, US 1 hits a shitload of major cities along the east coast, starting with:
ME: Brunswick, Portland
NH: Portsmouth
MA: Boston
RI: Providence
CT: New Haven, Bridgeport, Stamford
NY: Bronx, Manhattan
NJ: Jersey City, Newark, Woodbridge (Township), New Brunswick, Trenton
PA: Philadelphia
MD: Baltimore
DC: Washington
VA: Richmond
NC: Raleigh
SC: Columbia
GA: Augusta
FL: Jacksonville, Port St Lucie, Miami
So, US 1 hits 24 major cities along it's entire length. It hits the most in New Jersey with 5. Do any other major US Highways pass through a close number of major cities within states?
FYI: My definition of "major city" is a city that is more important to your state than others. Most of the time, these are the cities mentioned by the state as their "core" cities. Feel free to post it anyway if you are unsure.
Since it's my avatar, I'll start with US 76. Really not much at all, lol.
Tennessee: Chattanooga
Georgia: no large cities
South Carolina: Columbia
North Carolina: Wilmington
I feel like this is going to be impossible without a better, less subjective definition of major cities. For instance, if I were making the list, I'd definitely include a couple of Florida cities that are definitely more major than Woodbridge (Daytona for example???), and recognize that by any definition, Bronx and Manhattan are not separate cities.
I'll go with the US Route I'm most familiar with, US 6.
CA: Formerly Los Angeles and Long Beach, but not anymore
NV: really nothing
UT: Provo's southern suburbs
CO: Denver
NE: Lincoln, Omaha
IA: Des Moines, Iowa City, Davenport
IL: Chicago's southern suburbs
IN: NW Indiana (should probably be considered part of Chicago's southern suburbs)
OH: Cleveland
PA: Scranton
NY: Not much of anything
CT: Danbury, Hartford
RI: Providence
MA: Fall River
That's between 13 and 15, depending on how you look at it. For a cross-country route, it doesn't hit much of anything.
I-10: Los Angeles, Phoenix, Tucson, El Paso, San Antonio, Houston, New Orleans and Jacksonville.
Quote from: Kacie Jane on October 09, 2014, 12:28:03 AM
I feel like this is going to be impossible without a better, less subjective definition of major cities. For instance, if I were making the list, I'd definitely include a couple of Florida cities that are definitely more major than Woodbridge (Daytona for example???), and recognize that by any definition, Bronx and Manhattan are not separate cities.
Maybe an easier way to put it is cities with a population of at least 70k? Major Cities IMO are ones that you generally know by name when referring to the state in question. Except with this criteria, New Brunswick isn't considered a major city since it only has 55k people, but I still think it's major (as it hosts the de-facto state college of New Jersey). That's why I'm reluctant to use a population size as an indicator. That's why I opted for the posting of cities that people think are major in their respective states.
Quote from: Zeffy on October 09, 2014, 10:35:08 AM
Quote from: Kacie Jane on October 09, 2014, 12:28:03 AM
I feel like this is going to be impossible without a better, less subjective definition of major cities. For instance, if I were making the list, I'd definitely include a couple of Florida cities that are definitely more major than Woodbridge (Daytona for example???), and recognize that by any definition, Bronx and Manhattan are not separate cities.
Maybe an easier way to put it is cities with a population of at least 70k? Major Cities IMO are ones that you generally know by name when referring to the state in question. Except with this criteria, New Brunswick isn't considered a major city since it only has 55k people, but I still think it's major (as it hosts the de-facto state college of New Jersey). That's why I'm reluctant to use a population size as an indicator. That's why I opted for the posting of cities that people think are major in their respective states.
Exactly. What defines a "major city" varies from state to state, and from area to area. Marquette is a major city in Michigan's UP despite only having a population of 21k. Livonia, next to Detroit, has a population four times that amount, but is not a major city as it is merely part of a larger metro area.
A cutoff of 70k leaves out every city in West Virginia, Wyoming, Maine, and Vermont.
Quote from: Brandon on October 09, 2014, 10:45:22 AM
Exactly. What defines a "major city" varies from state to state, and from area to area. Marquette is a major city in Michigan's UP despite only having a population of 21k. Livonia, next to Detroit, has a population four times that amount, but is not a major city as it is merely part of a larger metro area.
A cutoff of 70k leaves out every city in West Virginia, Wyoming, Maine, and Vermont.
I leave it to the opinion of the poster on their definition of whether or not a city is major enough. My criteria I used was:
* State Capitals (obviously)
* Major state college towns (I.E. New Brunswick and Rutgers)
* Heavily developed city (in comparison to others in the state)
The criteria is vague, but that's why I've left it up to the poster on whether or not they want to list it. Pianocello's list is a good example of what I'm looking for.
US 3
MA: Cambridge
NH: Nashua, Manchester, Concord
US 5
CT: New Haven, Hartford
MA: Springfield
VT: Not really any major US cities, however many cities can be considered "large" on a Vermont scale. These cities I would count as Brattleboro, White River JCT. (Hartford), and St. Johnsbury.
US 44
NY: Poughkeepsie
CT: Hartford
RI: Providence
MA: On a historical scale, US 44 ends in Plymouth, MA.
US 7
CT: Norwalk, Danbury
MA: Pittsfield
VT: Rutland, Burlington
US 30:
NJ: Atlantic City, Camden
PA: Philadelphia, Lancaster, York, Gettysburg, Pittsburgh
WV: <nothing qualified as major>
OH: Canton, Mansfield*
IN: Fort Wayne
IL: Joliet
IA: Cedar Rapids
NE: <nothing qualified as major>*
WY: Cheyenne
ID: Twin Falls, Boise
OR: Portland, Astoria
* Means that I wasn't sure on whether or not it should be listed
Quote from: JakeFromNewEngland on October 09, 2014, 06:05:34 PM
US 3
MA: Cambridge
NH: Nashua, Manchester, Concord
US 5
CT: New Haven, Hartford
MA: Springfield
VT: Not really any major US cities, however many cities can be considered "large" on a Vermont scale. These cities I would count as Brattleboro, White River JCT. (Hartford), and St. Johnsbury.
US 44
NY: Poughkeepsie
CT: Hartford
RI: Providence
MA: On a historical scale, US 44 ends in Plymouth, MA.
US 7
CT: Norwalk, Danbury
MA: Pittsfield
VT: Rutland, Burlington
I would also include Lowell MA for US 3.
Why is Port St. Lucie a major city for US 1?
Quote from: hbelkins on October 09, 2014, 07:14:36 PM
Why is Port St. Lucie a major city for US 1?
PSL has roughly 170k people, and it's a growing city in FL. But agreeing with someone else, for US 1 in FL, I would have put Daytona Beach as well. I would have also added Ft. Lauderdale (even though it's in the Miami Metropolitan Area, it's still a pretty large city), and possibly even Titusville.
U.S. 11
Louisiana: Slidell
Mississippi: Hattiesburg, Meridian
Alabama: Tuscaloosa, Birmingham (bypasses Gadsden)
Georgia: Nothing
Tennessee: Chattanooga, Knoxville, Bristol
Virginia: Roanoke
West Virginia: Martinsburg
Maryland: Hagerstown
Pennsylvania: Harrisburg, Wilkes-Barre, Scranton
New York: Binghamton, Syracuse
US 31
Alabama: Montgomery, Hoover, Birmingham
Tennessee: Nashville
Kentucky: Bowling Green, Louisville
Indiana: Jeffersonville, Indianapolis, West Lafayette, Gary
(cities in italics may not qualify as major, depending on your criteria, but all do have significant regional importance.)
US-101
Los Angeles
Oxnard
Ventura
Santa Barbara
Santa Maria
San Luis Obispo
Salinas
San Jose
San Francisco
Santa Rosa
Eureka
Coos Bay
Astoria
Aberdeen
Port Angeles
Olympia
One could argue that there's only three major cities on this list (Los Angeles, San Francisco, San Jose), which might make US-101 a candidate for fewest major cities per mile?
Quote from: Charles2 on October 09, 2014, 09:25:20 PM
US 31
Alabama: Montgomery, Hoover, Birmingham
Tennessee: Nashville
Kentucky: Bowling Green, Louisville
Indiana: Jeffersonville, Indianapolis, West Lafayette, Gary
I presume you meant South Bend.
Why not include Benton Harbor/St Joe, Holland, Grand Haven, Muskegon and Traverse City?
Quote from: DTComposer on October 09, 2014, 11:25:13 PM
One could argue that there's only three major cities on this list (Los Angeles, San Francisco, San Jose), which might make US-101 a candidate for fewest major cities per mile?
US 2.
US 1 should include Edison for New Jersey as it is the fourth largest city in NJ.
West Palm Beach, FL is very large and notable I might add.
Daytona Beach has the famous speedway.
Petersburg/ Colonial Heights needs mentioning for Virginia for sure.
Quote from: GaryV on October 10, 2014, 07:54:06 AM
Quote from: Charles2 on October 09, 2014, 09:25:20 PM
US 31
Alabama: Montgomery, Hoover, Birmingham
Tennessee: Nashville
Kentucky: Bowling Green, Louisville
Indiana: Jeffersonville, Indianapolis, West Lafayette, Gary
I presume you meant South Bend.
Why not include Benton Harbor/St Joe, Holland, Grand Haven, Muskegon and Traverse City?
I think he mightve gotten mixed up and thought US 31 ended in Gary, as well as I-65 does. But US 31 does end its time being parallel to I-65 in Indianapolis, then goes north into northern Indiana, then into Michigan.
If I made the assumption that US 31 ended in Gary some on here would have a field day with me lol!
Anyway yes I have to agree with this. He obviously thought US 31 and I-65 are always joined at the hip.
Quote from: roadman65 on October 10, 2014, 08:29:15 AM
US 1 should include Edison for New Jersey as it is the fourth largest city in NJ.
I vote no. Both Woodbridge and Edison are large townships, not cities. They are a) characteristically different from cities, and b) not generally considered "major" by anyone not in their immediate area, at least in part because of a).
Also, not to nitpick (as I proceed to anyway), but Newark, Jersey City, Paterson, and Elizabeth are all bigger than either.
I put iffy ones with question marks. Tell me what you think. I feel like it's hard to not be biased with your home state. Some of the Louisiana ones I know aren't as big as cities in other states, but maybe in my mind it's because Louisiana has a decent amount of destinations on BGS's.
US 90:
Texas: San Antonio, Houston, Beaumont
Louisiana: Lake Charles, Lafayette, (Morgan City? or previously Houma?), New Orleans
Mississippi: Gulfport
Alabama: Mobile
Florida: Pensacola, Tallahassee, Jacksonville
US 80
Texas: Dallas, Longview?
Louisiana: Shreveport, Monroe
Mississippi: Vicksburg?, Jackson, Meridian
Alabama: Montgomery
Georgia: Columbus, Macon, Savannah
Historic 80:
Texas: also Abilene, El Paso
New Mexico: Las Cruces?
Arizona: Tucson, Yuma?
California: San Diego
Quote from: bassoon1986 on October 10, 2014, 11:09:56 AM
Historic 80:
Arizona: Tucson, Yuma?
Nit-picking here, but didn't US 80 go through Phoenix at one point?
And to actually contribute something to the thread, I'll do US 27 (historic in parenthesis):
MI: (Lansing)
IN: Fort Wayne
OH: Cincinnati
KY: Lexington
TN: Chattanooga
GA: Columbus
FL: Tallahassee, Disney area, Miami
Quote from: pianocello on October 10, 2014, 02:03:45 PM
Quote from: bassoon1986 on October 10, 2014, 11:09:56 AM
Historic 80:
Arizona: Tucson, Yuma?
Nit-picking here, but didn't US 80 go through Phoenix at one point?
Indeed (it was AZ 84 that I-8 followed east from Gila Bend to Casa Grande, while US 80 followed today's AZ 85 north, then what later became (but no longer is) the east-west section of AZ 85 from Buckeye to Phoenix).
Quote from: TheStranger on October 10, 2014, 02:25:16 PM
Quote from: pianocello on October 10, 2014, 02:03:45 PM
Quote from: bassoon1986 on October 10, 2014, 11:09:56 AM
Historic 80:
Arizona: Tucson, Yuma?
Nit-picking here, but didn't US 80 go through Phoenix at one point?
Indeed (it was AZ 84 that I-8 followed east from Gila Bend to Casa Grande, while US 80 followed today's AZ 85 north, then what later became (but no longer is) the east-west section of AZ 85 from Buckeye to Phoenix).
Yes! Thanks for that correction.
I know I've mentioned this before on here at some point but a while back I took sum of the population of the top 10 metropolitan areas along each of the major 0-ending east-west U.S. routes and then divided that by the highway's mileage to figure out the "least dense" of those routes. This thread has finally inspired me to dig up that spreadsheet. Here's the results, for anyone who might be interested:
Note that this was done pretty un-scientifically and the top 10 metros along each route were basically determined just by eyeballing each route. I've also updated the figures to match the latest 2013 Census Bureau update. And, of course, the methodology itself is certainly wide open for debate.
U.S. 20
Chicago (9,537,289)
Boston (4,684,299)
Cleveland (2,064,725)
Buffalo (1,134,155)
Albany (877,905)
Boise (650,288)
Springfield, MA (626,915)
Toledo (608,145)
Rockford, IL (344,623)
South Bend (318,586)
TOTAL: 20,846,930
/ 3,365 mi = 6,195.22 "people per mile"
U.S. 30
Chicago [by virtue of Joliet, which is considered part of the Chicago MSA] (9,537,289)
Philadelphia (6,034,678)
Pittsburgh (2,360,867)
Portland, OR (2,314,554)
Omaha (895,151)
Boise (650,288)
Lancaster, PA (529,600)
Fort Wayne (424,122)
Canton (403,707)
Atlantic City (275,862)
TOTAL: 23,426,118
/ 3,073 mi = 7,623.21 "people per mile"
U.S. 40
Philadelphia [by virtue of Wilmington, which is considered part of the Philly MSA] (6,034,678)
St. Louis (2,810,056)
Baltimore (2,770,738)
Denver (2,697,476)
Kansas City (2,054,473)
Columbus (1,967,066)
Indianapolis (1,953,961)
Salt Lake City (1,140,483)
Dayton (802,489)
Atlantic City (275,862)
TOTAL: 22,507,282
/ 2,285 mi = 9,850.01 "people per mile"
U.S. 50
Washington, DC (5,949,859)
St. Louis (2,810,056)
Sacramento (2,215,770)
Cincinnati (2,137,406)
Kansas City (2,054,473)
Pueblo, CO (161,451)
Jefferson City (150,494)
Grand Junction (147,554)
Winchester, VA (131,980)
Parkersburg, WV (92,470)
TOTAL: 15,851,513
/ 3,008 mi = 5,269.78 "people per mile"
U.S. 60
Phoenix (4,398,762)
Hampton Roads (1,707,369)
Louisville (1,262,261)
Richmond (1,245,764)
Lexington, KY (489,435)
Springfield, MO (448,744)
Huntington, WV (364,101)
Amarillo (258,196)
Charleston, WV (224,743)
Paducah, KY (98,765)
TOTAL: 10,498,140
/ 2,670 mi = 3,931.89 "people per mile"
U.S. 70
Nashville (1,757,912)
Memphis (1,341,746)
Raleigh (1,214,516)
Knoxville (852,715)
Greensboro (741,065)
Little Rock (724,385)
Durham (534,578)
Asheville (437,657)
Hickory (363,572)
Las Cruces (213,460)
TOTAL: 8,181,606
/ 2,385 mi = 3,430.44 "people per mile"
And just for fun, I added a couple more just now:
U.S. 6
Chicago (9,537,289)
Denver (2,697,476)
Cleveland (2,064,725)
Providence (1,604,291)
Hartford (1,215,211)
Omaha (895,151)
Des Moines (599,789)
Provo (562,239)
Scranton (562,037)
Davenport, IA (383,681)
TOTAL: 20,121,889
/ 3,205 mi = 6,278.28 "people per mile"
U.S. 2
Seattle (3,610,105)
Spokane (535,724)
Duluth (279,887)
Burlington (214,796)
Bangor (153,364)
Wenatchee (113,438)
Grand Forks (100,748)
Kalispell (93,068)
Minot (46,321)
Williston (20,850)
TOTAL: 5,168,301
/ 2,571 mi = 2,010.23 "people per mile"
Even if you complete the route through Canada (which bumps the bottom three for Montreal, Ottawa, and Sudbury), it jumps to 3,159.27 people per mile, still the smallest of the ones I've done.
And finally, a personal favorite of mine,
U.S. 62
Columbus (1,967,066)
Oklahoma City (1,319,677)
Buffalo (1,134,155)
El Paso (831,036)
Youngstown (555,506)
Fayetteville, AR (491,966)
Canton (403,707)
Lubbock (301,038)
Lawton (131,089)
Paducah (98,765)
TOTAL: 7,234,005
/ 2,248 mi = 3,217.97 "people per mile"
Quote from: Zeffy on October 09, 2014, 06:12:35 PM
US 30:
NJ: Atlantic City, Camden
PA: Philadelphia, Lancaster, York, Gettysburg, Pittsburgh
WV: <nothing qualified as major>
OH: Canton, Mansfield*
IN: Fort Wayne
IL: Joliet
IA: Cedar Rapids
NE: <nothing qualified as major>*
WY: Cheyenne
ID: Twin Falls, Boise
OR: Portland, Astoria
* Means that I wasn't sure on whether or not it should be listed
At the least, Grand Island should be listed for Nebraska. GI, Hastings and Kearney sometimes get lumped together as one area, although it's really 3 cities with a lot of farmland between each other.
Quote from: GaryV on October 10, 2014, 07:54:06 AM
Quote from: Charles2 on October 09, 2014, 09:25:20 PM
US 31
Alabama: Montgomery, Hoover, Birmingham
Tennessee: Nashville
Kentucky: Bowling Green, Louisville
Indiana: Jeffersonville, Indianapolis, West Lafayette, Gary
I presume you meant South Bend.
Why not include Benton Harbor/St Joe, Holland, Grand Haven, Muskegon and Traverse City?
Call it a brain fart.
Benton Harbor, or Chicken Man? (He's everywhere! He's everywhere!) :-D
Quote from: DandyDan on October 10, 2014, 07:14:44 PM
Quote from: Zeffy on October 09, 2014, 06:12:35 PM
US 30:
NJ: Atlantic City, Camden
PA: Philadelphia, Lancaster, York, Gettysburg, Pittsburgh
WV: <nothing qualified as major>
OH: Canton, Mansfield*
IN: Fort Wayne
IL: Joliet
IA: Cedar Rapids
NE: <nothing qualified as major>*
WY: Cheyenne
ID: Twin Falls, Boise
OR: Portland, Astoria
* Means that I wasn't sure on whether or not it should be listed
At the least, Grand Island should be listed for Nebraska. GI, Hastings and Kearney sometimes get lumped together as one area, although it's really 3 cities with a lot of farmland between each other.
If Twin Falls counts, I would add in Pocatello (bigger than Twin, home of Idaho State University), Laramie (Wyoming's third largest city, home to UWyo, probably the cultural capital of Wyoming), North Platte (very important regional center and rail hub), Grand Island (bigger than Twin, also an important regional center), and Ames (bigger than Twin, home to Iowa State). Rock Springs would also fit the mold of Twin Falls and North Platte as small, but a significant regional hub.
Curious how US 60 turns out if you un-truncate it and run it back to the East LA Interchange (where it really should end, damnit). LA and Riverside would bump the bottom 2 off the list.
My personal favorite, US 41. Now climb in the backseat of a Greyhound bus and ride along...
WI-Green Bay, Appleton, Milwaukee
IL-Chicago
IN-Hammond, Terre Haute, Evansville
TN-Clarksville, Nashville, Chattanooga
GA-Atlanta, Macon
FL-Tampa, Sarasota, Ft. Myers, Naples, Miami
Montana
US 2:
Libby, Kalispell, Whitefish, Columbia Falls, Glasgow, Cut Bank, Shelby, Havre, after Havre, US 2 is mainly passing rural farm communities like Wolf Point clear up to Willison, ND
US 12 with Interstate 90:
Missoula metro, Lolo, Bonner-Milltown, Drummond, Butte
US 12 with US 287:
Helena metro, Townsend
US 12 with US 89:
White Sulphur Springs
US 12 with US 191:
Harlowtown
US 12 with US 87:
Roundup
US 12 alone:
Forsyth, Miles City
US 87 alone:
Billings, Roundup, Fort Benton, Big Sandy, Box Elder, after that, it ends near Havre
US 87 with US 89, US 191, Interstate 15, Montana Highway 3 and Montana Highway 200:
Lewistown, Great Falls metro, Vaughn,
US 89 alone:
Yellowstone National Park, Gardiner, Livingston, Wilsall, Choteau, Browning, Port of Carway
US 93:
Eureka, Kalispell, Polson, Ravalli, Arlee, Missoula metro, Florence, Stevensville, Hamilton, Darby, Sula
US 191:
West Yellowstone, Bozeman metro, Livingston (coupled with I-90), Big Timber, Harlowtown, Lewistown, Malta, Port of Monarchy
US 212:
Red Lodge, Laurel, Billings metro, Lockwood, Lame Deer, Alzada
US 212 with Montana Highway 59:
Broadus
US 212 with US 87 and Interstate 90:
Hardin, Crow Agency
US 287:
West Yellowstone (couple with US 191), Townsend, then it's a long stretch with US 12, Interstate 15, up to the split at Exit 228, then another long jaunt to Augusta up to Choteau (meeting up with US 89),
US 310:
Laurel, Fromberg, Bridger
I'll do a shorter one, US-97:
CA: None
OR: Klamath Falls, Bend
WA: Yakima, Wenatchee
Total: 4
US 195
ID: None
WA: Pullman (29,799), Spokane (208,916)
US 411:
Alabama: Eastern Birmingham Metro Area (I guess that could count, as it starts in Leeds), & Gadsden (questionable if it's large enough)
Georgia: Rome (also questionable)
Tennessee: Maryville (possibly, but at least the southern Knoxville Metro Area)
That's about it for that.
US 278:
South Carolina: Hilton Head Island
Georgia: Augusta, Atlanta
Alabama: Gadsden
Mississippi: Tupelo, Greenville
Quote from: mjb2002 on November 21, 2014, 06:38:05 PM
US 278:
South Carolina: Hilton Head Island
Georgia: Augusta, Atlanta
Alabama: Gadsden
Mississippi: Tupelo, Greenville
Adding Arkansas: None
US 61:
LA: New Orleans
MS: Vicksburg, Natchez
TN: Memphis
MO: St. Louis
IA: Dubuque, Quad Cities
WI: La Crosse
MN: Winona, St. Paul
No longer serves: Duluth
I don't get this thread.
US-50
Sacramento, CA
Kansas City, MO
Saint Louis, MO
Cincinnati, OH (https://en.wikipedia.org/wiki/Cincinnati,_Ohio)[/font]
Washington DC and Ocean City, MD
Previous Sections of US-50
once had Stockton, CA, Oakland, CA and San Francisco, CA.
US-40 Once included Sacramento, Oakland and San Francisco at one point.
US 99 (Historic)+BC 99
El Centro
San Bernardino
Los Angeles
Bakersfield
Fresno
Stockton
Sacramento
Woodland (W)/Chico (E)
Redding
Weed
Medford
Grants Pass
Roseburg
Eugene
Corvallis (W)/Salem (E)
McMinnville (W)
Portland
Vancouver
Kelso
Centralia
Olympia
Tacoma
Seattle
Everett
Belingham
Vancouver
Whistler
US 97
Weed
Klamath Falls
Bend
Yakima
Wenatchee
Okanogan
Kamloops
Prince George
Dawson Creek
I think in this case, the relative size of the cities goes down the further north you go, bu they retain their 'importance' because there's nothing else around. Besides that moose.
US-23, my avatar, from north to south:
MI: Mackinaw City
Saginaw
Flint
Ann Arbor
OH: Toledo
Marion
Delaware
Columbus
Portsmouth
KY: Pikeville
Ashland
VA: none
TN: Kinsport
Johnson City
NC: Asheville
GA: Atlanta
Macon
FL: Jacksonville
Quote from: TheHighwayMan394 on November 22, 2014, 10:40:12 PM
US 61:
LA: New Orleans
MS: Vicksburg, Natchez
TN: Memphis
MO: St. Louis
IA: Dubuque, Quad Cities
WI: La Crosse
MN: Winona, St. Paul
No longer serves: Duluth
Can definitely add Baton Rouge to the list.
US 8: none
Quote from: wphiii on October 10, 2014, 02:40:16 PM
I know I've mentioned this before on here at some point but a while back I took sum of the population of the top 10 metropolitan areas along each of the major 0-ending east-west U.S. routes and then divided that by the highway's mileage to figure out the "least dense" of those routes. This thread has finally inspired me to dig up that spreadsheet. Here's the results, for anyone who might be interested:
Note that this was done pretty un-scientifically and the top 10 metros along each route were basically determined just by eyeballing each route. I've also updated the figures to match the latest 2013 Census Bureau update. And, of course, the methodology itself is certainly wide open for debate.
U.S. 20
Chicago (9,537,289)
Boston (4,684,299)
Cleveland (2,064,725)
Buffalo (1,134,155)
Albany (877,905)
Boise (650,288)
Springfield, MA (626,915)
Toledo (608,145)
Rockford, IL (344,623)
South Bend (318,586)
TOTAL: 20,846,930
/ 3,365 mi = 6,195.22 "people per mile"
U.S. 30
Chicago [by virtue of Joliet, which is considered part of the Chicago MSA] (9,537,289)
Philadelphia (6,034,678)
Pittsburgh (2,360,867)
Portland, OR (2,314,554)
Omaha (895,151)
Boise (650,288)
Lancaster, PA (529,600)
Fort Wayne (424,122)
Canton (403,707)
Atlantic City (275,862)
TOTAL: 23,426,118
/ 3,073 mi = 7,623.21 "people per mile"
U.S. 40
Philadelphia [by virtue of Wilmington, which is considered part of the Philly MSA] (6,034,678)
St. Louis (2,810,056)
Baltimore (2,770,738)
Denver (2,697,476)
Kansas City (2,054,473)
Columbus (1,967,066)
Indianapolis (1,953,961)
Salt Lake City (1,140,483)
Dayton (802,489)
Atlantic City (275,862)
TOTAL: 22,507,282
/ 2,285 mi = 9,850.01 "people per mile"
U.S. 50
Washington, DC (5,949,859)
St. Louis (2,810,056)
Sacramento (2,215,770)
Cincinnati (2,137,406)
Kansas City (2,054,473)
Pueblo, CO (161,451)
Jefferson City (150,494)
Grand Junction (147,554)
Winchester, VA (131,980)
Parkersburg, WV (92,470)
TOTAL: 15,851,513
/ 3,008 mi = 5,269.78 "people per mile"
U.S. 60
Phoenix (4,398,762)
Hampton Roads (1,707,369)
Louisville (1,262,261)
Richmond (1,245,764)
Lexington, KY (489,435)
Springfield, MO (448,744)
Huntington, WV (364,101)
Amarillo (258,196)
Charleston, WV (224,743)
Paducah, KY (98,765)
TOTAL: 10,498,140
/ 2,670 mi = 3,931.89 "people per mile"
U.S. 70
Nashville (1,757,912)
Memphis (1,341,746)
Raleigh (1,214,516)
Knoxville (852,715)
Greensboro (741,065)
Little Rock (724,385)
Durham (534,578)
Asheville (437,657)
Hickory (363,572)
Las Cruces (213,460)
TOTAL: 8,181,606
/ 2,385 mi = 3,430.44 "people per mile"
And just for fun, I added a couple more just now:
U.S. 6
Chicago (9,537,289)
Denver (2,697,476)
Cleveland (2,064,725)
Providence (1,604,291)
Hartford (1,215,211)
Omaha (895,151)
Des Moines (599,789)
Provo (562,239)
Scranton (562,037)
Davenport, IA (383,681)
TOTAL: 20,121,889
/ 3,205 mi = 6,278.28 "people per mile"
U.S. 2
Seattle (3,610,105)
Spokane (535,724)
Duluth (279,887)
Burlington (214,796)
Bangor (153,364)
Wenatchee (113,438)
Grand Forks (100,748)
Kalispell (93,068)
Minot (46,321)
Williston (20,850)
TOTAL: 5,168,301
/ 2,571 mi = 2,010.23 "people per mile"
Even if you complete the route through Canada (which bumps the bottom three for Montreal, Ottawa, and Sudbury), it jumps to 3,159.27 people per mile, still the smallest of the ones I've done.
And finally, a personal favorite of mine,
U.S. 62
Columbus (1,967,066)
Oklahoma City (1,319,677)
Buffalo (1,134,155)
El Paso (831,036)
Youngstown (555,506)
Fayetteville, AR (491,966)
Canton (403,707)
Lubbock (301,038)
Lawton (131,089)
Paducah (98,765)
TOTAL: 7,234,005
/ 2,248 mi = 3,217.97 "people per mile"
Did you leave out one of the most famous of all US routes, US 66, because it has been decommissioned? It hit some major cities, Chicago, St. Louis, OKC, and LA.