National Highway System redux

[Dirt Roads]

I've been watching this subthread on I-587 (Zebulon-Greenville) and it is reminding me of the old MTR discussions on the National Highway System.

This is interesting.  Another NC Interstate designated to a US Route freeway.  I am amazed just at how many interstates have been granted to the Tar Heel State.  I knew this one was going to be one eventually, but IMO I think that 587 is not the right number for it.  Heck an even number x87 would work being it connects with two other (or it will someday) interstates.

The interesting part is they moved over the existing US routes onto these freeways and now the move over seems irrelevant now.  The old roads being mostly alternate routes of it, could have been left as is and the new freeways could have been designated as interstates to the get go.  Now, we have the unnecessary concurrency.

VDOT did that with transferring VA 168 to VA 143.  It moved it on to I-64 only to have it decommissioned later so time and funds were wasted in altering an alignment to be later removed.  Yes, I know that NCDOT won't remove US 264 like VDOT did to truncating VA 168, but still its a waste. You now have the burden with extra money of adding new shields and all for that if they had known originally that it would be part of the interstate system, US 264 would have remained its surface road alignment.

Everyone must remember NCDOT's goal for 50 years has been to bring a modern, 4-lane. divided highway to within 10 miles of 96% of the population, one that is every evenly spread across the state in every nook and cranny.

So what you see is a continued realization of the state being crisscrossed by hundreds of 4-lane divided highways about every 20 miles statewide.

Therefore the interstates will differentiate those routes from all the 4-lane highways that ultimately will be the only road type practically in the future.

Agreed.  I've never liked the idea of having a useless overlap between a US route (or any other route) and an interstate when the original alignment is still available and decent.  IMO keep the overlaps to where necessary and don't have overlaps for the sake of having overlaps.

Wouldn't it be desirable to use the best and safest roadway for all routes when they have a chance to piggyback on a big interstate?  Wouldn't it be faster too?

[Dirt Roads]

When the National Highway System was first proposed in the early-1990s, I was hopeful that we would be working toward an integrated highway network (and away from a hodge-podge of political historic routes).  The US Route system (first implemented by the American Automobile Association) was soon co-opted by politician wanting to connect their hometowns and districts to the national network (to which I couldn't disagree).  But nearly 75 years later, we ended up with a confusing mess.  But by the time the National Highway System Designation Act got pulled together in 1995, there was a lot of the same political danglers mixed in along with the key routes.

The discussion above highlights that routes with local importance got short shrift when originally proposed for Interstate status, but later gets approved once AASHTO realizes that the state is serious enough to produce a corridor that will eventually meet Interstate standards.

We can argue about how Interstate standards are too stringent and therefore costly, but back in those days I was hoping for a new NHS highway designation that would mimic the lettered corridors used by the Appalachian Highway Commission.  In particular, I was impressed that in Great Britain they can begin to upgrade a primary highway to Motorway requirements and simply change the route designation to flag the improvements.  The first example that I saw was the A1 being upgraded to A1(M).  After 25 years, we still don't have anything helpful for drivers to identify which roads other than Interstates are high-speed corridors.  Worse, because of GPS usage almost nobody other than us roadgeeks know how to use a map anymore.

Please keep your comments towards policy issues here. 

[Dirt Roads]

Just looking at Maryland, North Carolina, Virginia and West Virginia, I am finding several themes with respect to the National Highway System.  Using common language for now, but it would be wise for us to consider how to develop professional descriptions so that we can eventually make some serious proposals for real improvements.  Not wanting to bring up the old arguments, but for this particular post the use of the word "highway" is intended to mean four-lane arterials already interconnected to the Interstate system.  Also, the word "highway" is being used in a generic sense to describe a general traffic corridor and not necessarily follow a particular established numbered route.

• There are very few highways that appear to meet Interstate standards that are not already included.

• There are only a handful of highways that are Limited Access, not meeting current Interstate Standards that ought to be included.  With the exception of West Virginia, it is very difficult to determine which highways are Partially Limited Access.  It is sometimes difficult to determine which highways are Multilane Divided.  With the goal being to identify higher-speed highways connected to the Interstate system, experience with all of these routes indicates that they could be separated further into categories related to traffic congestion during off-peak hours.

• There are only a handful of highways that cross state boundaries.

• There are a good number of highways that interconnect with the Interstate system in more than one location, sometimes at both ends.  Some of the remaining highways are in corridors that could be interconnected at both ends, and ought to be flagged as such.

• The remainder of the highways (considered spurs for this discussion) are generally interconnected to other highways rather than the Interstate system (even when they intersect the Interstate system).  Only a handful of these spurs appear as corridors that serve to connect cities/towns to the Interstate system.  There are also a good number of spurs that serve endpoint cities/towns but don't quite make it all the way.  For these four states, spurs tend to spiral out from Interstate system or other highways (as opposed to some states where spurs are intersecting those routes at a perpendicular that doesn't make for a good route).

With respect to the National Highway System, North Carolina has made significant progress toward upgrading its High Priority Corridors to Limited Access highways.  Virginia and West Virginia have not.  Maryland has completed MD-200 (Intercounty Connector) as a toll facility.  Some reconsideration of the original ISTEA High Priority Corridors appears to be needed.  Additionally, there are several larger cities elsewhere (think Bend, Oregon) that are still not connected to the Interstate system with highways that need some consideration.

All four of these states are part of the Appalachian Regional Commission, and a good number of Appalachian Development Highway System routes are highways that are interconnected to the Interstate system and other highways in these states.  North Carolina and West Virginia have made some progress over the past 25 years.  Maryland has not made progress towards completion of Corridor N (US-219 northward from Grantsville).  Virginia has done some big work in the past 25 years, but I'm not sure about progress.

[Dirt Roads]

North Carolina

Limited Access highways (over 20 miles)

• Raleigh to Rocky Mount to Williamston (US-64)
• Raleigh to Wilson to Greenville (US-264)
• Raleigh to Sanford (US-1)
• Winston-Salem to Mount Airy to I-77 (US-52//I-74)
• Hickory to Lincolnton to Bessemer City (US-321), not quite all the way to I-85

Multi-state routes (over 20 miles):

• Wilmington to Myrtle Beach to Socastee (US-17//SC-31)
• Monroe to Hartsville to Darlington to Florence (US-601//SC-151)
• Charlotte to Lancaster(US-501)
• Flat Rock to Greenville (US-25)

• Kitty Hawk to Moyock to Chesapeake (NC-168/VA-68)
• Williamston to Elizabeth City to Chesapeake (US-17)
• Greensboro to Danville to Lynchburg to Charlottesville (US-29)
• Greensboro to Martinsville to Roanoke (US-220)
• Winston-Salem to Wilkesboro (US-421)

Through routes (over 20 miles)

• Clayton to Smithfield to Goldsboro to New Bern   (US-70), short section in Kinston not qualifying
• New Bern to Jacksonville to Wilmington (US-17)
• Wilmington to Whiteville to Rockingham to Charlotte (US-74/I-74)
• Fayetteville to Sanford to Siler City to Greensboro (US-421)
• Gastonia to Shelby to Forest City to Columbia (US-74)

Spur routes (over 20 miles)

• Williamston to Columbia (US-64)
• Bethel to Greenville to Kinston to Pink Hill (US-13//NC-11)
• New Bern to Morehead City (US-70)
• Magnolia to Jacksonville to Morehead City (NC-24), short section through Beaulaville not qualifying
• Wilmington to Long Creek (US-421)
• Goldsboro to Mount Olive to Faison (US-117)
• Raleigh to Pittsboro to Asheboro (US-64)
• Henderson to Raleigh (US-1), short section of Capital Boulevard north of I-540 not qualifying
• Fayetteville to Elizabethtown (NC-87)
• Durham to Chapel Hill to Pittsboro (US-15/US-501)
• Greensboro to Asheboro to Rockingham (US-220)
• Salisbury to Statesville (US-70)
• Charlotte to Albemarle to Richfield (NC-24/NC-27//US-52)
• Charlotte to Pumpkin Center (NC-16)
• Wilkesboro to Boone (US-421)
• Mars Hill to Burnsville to Micaville (US-19//US-19E)
• Hickory to Lenoir to Boone (US-321)
• Clyde to Waynesville to Franklin to ending at Georgia Line (US-23)
• Sylva to Bryson City to Stecoah (US-19/US-74)

Not quite making the lists

• Durham to Roxboro (US-501), section through North Durham not qualifying

Future interstate numbers not shown (just to make things simpler).  Routes are intended to have average speeds in excess of 45 mph during non-rush periods, with some traffic signals.  I suspect that I missed some sections where these routes have issues and don't qualify yet.  For such a big state, the list looks to be manageable in this format.

[Dirt Roads]

Virginia

Limited Access highways (over 20 miles)

• Dulles Toll Road/Dulles Greenway (VA-267), all toll
• Centreville to Dulles to Sterling Park (VA-28), short section north of I-66 not yet qualifying
• Leesburg to Purcellville (VA-7)
• Chesapeake Expressway (VA-168), all toll, part of multi-state route

Multi-state routes (over 20 miles):

• Kitty Hawk to Moyock to Chesapeake (NC-168/VA-68)
• Williamston to Elizabeth City to Chesapeake (US-17)
• Greensboro to Danville to Lynchburg to Charlottesville (US-29)
• Greensboro to Martinsville to Roanoke (US-220)
• Winston-Salem to Wilkesboro (US-421)

• Virginia Beach to Exmore to Pocomoke City to Dover (US-13), portion of Chesapeake Bay Bridge/Tunnel only two lanes

• Ruther Glen to Bowling Green to Dahlgren to LaPlata (VA-207//US-301)
• Christiansburg to Blacksburg to Bluefield to Tazewell to Abingdon (US-460//US-19)
• Kingsport to Gate City to Big Stone Gap to Wise to Pikeville to Catlettsburg (US-23)

Through routes (over 20 miles)

• Purcellville to Winchester (VA-7)
• Dumfries to Manassas to Gainesville (VA-234)
• Newington to Fairfax to Reston to Herndon (VA-286), portion north of VA-267 is spur route
• Marshall to Warrenton (US-17), might not be long enough
• Opal to Fredericksburg (US-17)
• Culpeper to Fredericksburg (VA-3)
• Port Royal to Tappahannock (US-17)
• Tappahannock to Gloucester Point to Newport News (US-17), zig-zag at Tappahannock not qualified
• Mechanicsville to Tappahannock to Heathsville (US-360)
• Suffolk to Waverly to Petersburg (US-460)
• Suffolk to Emporia to South Hill to Danville to Stuart (US-58), portion west of Martinsville is spur route
• Richmond to Burkeville to South Boston (US-360)
• Petersburg to Farmville to Lynchburg to Roanoke (US-460//US-220A)

Spur routes (over 20 miles)

• Winchester to West Virginia Line (US-522)
• Winchester to Paris (US-50/US-17)
• Gainesville to Charlottesville (US-29), not yet connected to multi-state route
• Warrenton to Sperryville (US-211)
• New Kent to West Point to Glens (VA-33)
• Norfolk to Smithfield to Rushmore (VA-164/US-17//VA-10), portions connecting to Norfolk may not qualify
• Richmond to Powhatan (US-60)
• Daleville to Eagle Rock (US-220)
• Hillsville to Galax to Independence (US-58)
• Claypool Hill to Grundy (US-460)
• Hansonville to Coeburn to Norton (US-58A)

Not quite making the lists

• Winchester Bypass (VA-37), probably should be included for connectivity
• Winchester to Gore (US-50)
• Marumsco to Manassas to I-66 (VA-294), not continuous (hard turn at Minnieville), too much local access between Minnieville and Staples Mill
• Sandston to Toano (VA-33//US-60), roughly parallel to I-64, backtrack at Toano to I-64
  
• Pearisburg to Dublin (VA-100), various sections

Through routes and spur routes are better balanced in Virginia than North Carolina.  Did not include some of the interconnecting and spur routes in Northern Virginia because of the long rush hour periods.  Might need to downgrade VA-286 (Fairfax County Parkway), VA-234 and VA-294 (Prince William Parkway, didn't make the list) for same reason.  Otherwise, need to consider some additional rules for urban/suburban interconnectivity.

Future interstate numbers not shown (just to make things simpler).  Routes are intended to have average speeds in excess of 45 mph during non-rush periods, with some traffic signals. 

[Dirt Roads]

West Virginia

Limited Access highways (over 20 miles)

• Moon Township to Weirton to Steubenville (US-22)

Multi-state routes (over 20 miles):

• Chester to East Liverpool to Canfield OH to Mahoning Valley (US-30//OH-11)
• Clarksburg to Parkersburg to Porterfield OH (US-50)
• Beech Hill to Henderson to Gallipolis to Jackson to Chillicothe (US-35)
• Christiansburg to Blacksburg to Bluefield to Tazewell to Abingdon (US-460//US-19)

Through routes (over 20 miles)

• Sutton to Summersville to Beckley (US-19)
• Charleston to Logan to Williamson to Pikeville (US-119)

Spur routes (over 20 miles)

• Weston to Buckhannon to Elkins to Kerens (US-33//US-219)

Not quite making the lists

• Martinsburg to Charlestown (WV-9), too short, also short section of Apple Harvest Drive at I-81 not qualifying
• Scott Depot to Buffalo Bridge (US-35), too short but waiting extension to rest of US-35

[Dirt Roads]

Maryland

Limited Access highways (over 20 miles)

• Ellicott City to Severn to Pasadena (MD-100)
• Intercounty Connector toll (MD-200)
• Frederick to Weverton (US-340)
• Tuxedo to Bowie to Annapolis to Stevensville (US-50)

Multi-state routes (over 20 miles):

• Frederick to Thurmont to Gettysburg to Harrisburg (US-15)

• Queenstown to US-301 Toll Road DE (US-301)
• Ruther Glen to Bowling Green to Dahlgren to LaPlata (VA-207//US-301)
• Virginia Beach to Exmore to Pocomoke City to Dover (US-13), portion of Chesapeake Bay Bridge/Tunnel only two lanes

Through routes (over 20 miles)

• apparently none, due to technicalities

Spur routes (over 20 miles)

• Reisterstown to Westminster (MD-140)
• Queenstown to Cambridge (US-50)
• Wye Mills to Denton (MD-404)
• Cambridge to Salisbury to Ocean City (US-50)
• Salisbury to Ocean City MD (US-50)
• Forestville to Upper Marlboro to Prince Frederick to Solomons (MD-4//MD-2/MD-4)
• Oxon Hill to Indian Head (MD-210)

Not quite making the lists

• LaPlata to Brandywine to Temple Hills (US-301//MD-5), too much congestion between LaPlata and Brandywine
  
• Pinefield to Lexington Park (MD-5//MD-235), connection to US-301 no longer qualified as connecting to rest of system
• Forestville to Upper Marlboro to Prince Frederick to Solomons (MD-4), not a through route from US-301 for same reason

Hidden interstate number (err, I-595) not shown (just to make things simpler).  Routes are intended to still have average speeds in excess of 45 mph during non-rush periods, with some traffic signals (this is more difficult to be practicable in Maryland).  I suspect that I missed some sections where these routes have issues and don't qualify yet.  Also didn't include any routes that might have been improved since I clinched them.

Rant:  US-340 west of Frederick is one of the reasons for this thread.  When I lived in the DC area, I would recommend US-15/US-340 as a main route south to get out of Suburban Maryland at rush hour.  At the time, US-340 was Partially Limited Access with a left hand slip for US-15.  Folks would take the route and come back and complain that there was no way to look at the maps and tell how good the route was.  There needs to be a new system to differentiate higher-speed arterials from "primary" routes, many of which are no longer "primary".
[/quote]

[sparker]

Interestingly, some of the NHS (including the STRAHNET routes, essentially NHS with a military rationale tacked on) routes in the Far West tend to "straightline" the "point-A-to-point-B" concepts.  This is particularly true in NV, where the STRAHNET route traveling on US 395 in CA's Owens Valley shifts to US 6 north of Bishop and segues onto NV 360 to US 95, another such route.   Coincidentally, this route is part of the shortest path from L.A. to the Boise/Treasure Valley section of Idaho.  And in the eastern part of the state, the N-S NHS corridor nominally along US 93 shifts to NV 318 and US 6 between Ash Springs and Ely -- again, the shortest route and one with similar facility standards to the longer US 93 routing.  The formulators of at least this region's share of NHS routes seem to be determined to provide route efficiency above other considerations, all else being roughly equal. 

[Dirt Roads]

South Carolina

Limited Access highways (over 20 miles)

• Socastee to Nixons Crossroads (SC-31), part of mulit-state route
• Coolspring to Briarcliffe Acres (SC-22)

Multi-state routes (over 20 miles)

• Wilmington to Myrtle Beach to Socastee (US-17//SC-31)
• Monroe to Hartsville to Darlington to Florence (US-601//SC-151)
  
• Charlotte to Lancaster(US-501)
  
• Flat Rock to Greenville (US-25)
  

Through routes (over 20 miles)

• Cheraw to Bennettsville to Conway to Marion (SC-9//SC-38//US-501), spur route west of I-95
• Florence to Marion to Myrtle Beach (US-76//US-501)
• Chester to Lancaster (SC-9), spur route west of I-77
• Greenville to Clemson to Seneca to Westminster (US-123), spur route west of Seneca
• Columbia to Sumter to Kingsburg/Poston (US-378)
• Chareston to Ravenel to Coosawatchie (US-17)

Spur routes (over 20 miles)

• Blacksburg to York to Rock Hill (SC-5//SC-161), not quite a through route to I-85
• Clinton to Greenwood to Abbeville to Savannah River/Georgia Line (SC-72)
• Myrtle Beach to Georgetown (US-17)
• Charleston to Georgetown (US-17)

Not quite making the lists

• Spartanburg to Union (US-176), small section through Spartanburg not qualified
• Clemson to Walhalla (SC-28), too short, consider exemption as spur route
• North Augusta to Aiken (US-1), too short, consider exemption as spur route
• Kingsburg to Hemingway (SC-41/SC-51), too short
• Florence to Lake City to Moncks Corner to Summerville (US-52//US-17), both ends not qualified
• Myrtle Beach to Georgetown to Charleston (US-17), Georgetown not qualified for through route
• Georgetown to Andrews (US-17), too short, Georgetown not qualified for interconnection
• Santee to Orangeburg (US-301), too short, consider exemption as through route
• Orangeburg to Bamberg to Allendale (US-301), Orangeburg not qualified for interconnection
• Sheldon to Beaufort (US-21) too short, consider exemption as spur route
• Pritchardville to Beaufort (SC-170), too short
• Hardeeville to Hilton Head Island (US-278), too short, consider exemption as spur route

[Dirt Roads]

Georgia

Limited Access highways (over 20 miles)

• Sandy Springs to Roswell/Alpharetta to Cumming (GA-400)

Multi-state routes (over 20 miles)

• Columbus to Phenix City to Opelika (US-280/US-431)
• Thomasville to Bainbridge to Dothan (US-84)

• Colquitt to Bainbridge to Tallahassee (US-27)
• Thomasville to Tallahassee (US-319)
• Albany to Camilla to Thomasville to Monticello FL (US-19)
• Altamaha River to Baxley to Waycross to Callahan to Jacksonville (US-1//US-1/US-23)

Through routes (over 20 miles)

• Calhoun to Rome (GA-53)
• Rome to Bremen to LaGrange (US-27), spur south of I-20
• Cornelia to Commerce to Athens (US-441)
• Clarkesville to Toccoa to Lavonia (GA-17)
• Augusta to Waynesboro to Statesboro to Glennville (US-25), spur south of I-16
• Millen to Sylvania to Rincon to Savannah (GA-21)
• McDonough to Griffin to Americus to Albany (GA-20//US-19)
• Byron to Fort Valley to Columbus (GA-540//US-80)
  
• Macon to Sandersville to Augusta (GA-540//US-1)
• Perry to McRae to Jesup to Brunswick (US-341)
• Thomasville to Valdosta (US-84)

Spur routes (over 20 miles)

• Summerville to Rome (US-27)
• Nelson to Elijay to Blairsville (GA-5//GA-515//US-76)
• Gainesville to Clayton (US-23)
• Duluth to Lawrenceville to Athens (GA-316//US-29)
• Athens to Elberton (GA-72)
• Wadley to Swainsboro to Vidalia (US-1), spurs both sides of I-16
• Valdosta to Waycross to Jesup to Hinesville to Midway (US-84)

Not quite making the lists

• Ft. Oglethorpe to Summerville to Rome (US-27), short stretch east of Summerville two lanes
• Rome to Cartersville (US-411), not interconnected to I-75, consider as spur route from Rome
• Rome to Bremen to LaGrange (US-27), not interconnected to I-85
• Dalton to Chatsworth (US-76), too short
• Coal Mountain to Dalonega (US-19), too short, consider exemption as through route
• Dublin to Milledgeville to Eatonton (US-441), not interconnected to I-16
• Valdosta to Waycross to Jesup to Midway (US-84), not interconnected to I-95

[Dirt Roads]

Florida

Limited Access highways (over 20 miles)

• Florida's Turnpike toll (FL-91)
• Beachline toll (FL-528)
• Suncoast Parkway toll (FL-589)
• Western Beltway toll (FL-429)
• Wekiva Parkway toll (FL-414)
• Central Florida Greeneway toll (FL-417)
• Lakeland Polk Parkway toll (FL-570)
• Florida's Turnpike Homestead Extension toll (FL-821)
• Sawgrass Expressway toll (FL-869)
• Palmetto Expressway toll (FL-826)

Multi-state routes (over 20 miles)

• Colquitt to Bainbridge to Tallahassee (US-27)
• Thomasville to Tallahassee (US-319)
• Albany to Camilla to Thomasville to Monticello FL (US-19)
• Altamaha River to Baxley to Waycross to Callahan to Jacksonville (US-1//US-1/US-23

• Pensacola to Flomaton to Brewton (US-29)
• Panama City to Cottondale to Dothan (US-231)

Through routes (over 20 miles)

• Tallahassee to Perry to Chiefland to Ocala (US-27//US-19//Alt US-27//US-27)
• Weeki Wachee to Brooksville to Ridge Manor (FL-50), short spur east of I-75
• St. Cloud to Melbourne (US-192), short spur east of I-95
• Tampa to Bartow to Lake Wales to Indian Lake (FL-60), spur east of US-27
• Winter Haven to Bartow to Wauchula to Punta Gorda (US-17), spur north of FL-60
• Turnpike Exit 289 to Clermont to Lake Wales to Clewiston to Hialeah (US-27)
• Yeehaw Junction to Vero Beach (FL-60), spur route east of I-95
• Fort Pierce to Okeechobee (FL-70)
• Belle Glade to Wellington to West Palm Beach (US-98/US-441//US-98)

Spur routes (over 20 miles)

• Crestview to Ft. Walton Beach (FL-85)
• De Funiak Springs to Santa Rosa Beach (US-231)
• Yulee to Baldwin to Starke to Waldo to Ocala (US-301), through route north of I-10
• St. Augustine to East Palatka to San Mateo (FL-207//US-17)
• Gainesville to Palatka (FL-20), spur routes east and west of US-301
• Crystal River to Spring Hill to New Port Richey (US-19)
• Zephyrhills to Land O' Lakes to Elfers/New Port Richey (FL-54), spur east of I-75, west of Suncoast Parkway (FL-589)
• Fort Myers to Port LaBelle (FL-80)
• Hialeah Gardens to Homestead (Krome Avenue FL-997)
• Florida City to Key Largo to Tavernier (US-1)

Not quite making the lists

• Pensacola to Ft. Walton Beach to Panama City (US-98), too much congestion, consider spurs
• Baldwin to Starke to Waldo to Ocala (US-301), no interconnection to I-75
• Orange Park to Green Cove Springs to Palatka (US-17), too much congestion at I-295
• Gainesville to Palatka (FL-20), through route not interconnected to I-75 or I-295 via US-17
• DeLand to New Smyrna Beach (FL-44), too short, consider as cutoff route
• Ocala to Hernando (FL-200), short section of two-lane reduces length under 20 miles
• First Coast Expressway toll (FL-23 Limited Access), too short
• Orlando to Christmas to Titusville (FL-50), parallel to Beachline
• Bithlow/Christmas to Cocoa (FL-520), also served by Beachline
• Royal Palm Beach to Coconut Creek (US-441), parallel to Florida's Turnpike, consider exemption
• Dolphin Expressway toll (FL-836 Limited Access), too short, consider exemption
• Don Shula Expressway toll (FL-874 Limited Access), too short, consider exemption
• Snapper Creek Expressway toll (FL-878 Limited Access), too short
• Hialeah Gardens to Homestead (FL-997), through route not yet interconnected to US-1

Florida presents an interesting quandary.  There are a number of urban/suburban routes (non-Interstate) that serve/appear to serve as preferred bypasses creating suitable interconnections.  Urban/suburban routes in Jacksonville were deleted from this list because they do not increase the number of interconnections.  Some of the ones in the Miami area have also been deleted.

I was surprised how few through routes are in Northern Florida.  Obviously, the Panhandle routes connect to towns in Alabama and Georgia, but the main issue was limited interconnections along I-75 due to congested routes.

[Dirt Roads]

Interestingly, some of the NHS (including the STRAHNET routes, essentially NHS with a military rationale tacked on) routes in the Far West tend to "straightline" the "point-A-to-point-B" concepts.  This is particularly true in NV, where the STRAHNET route traveling on US 395 in CA's Owens Valley shifts to US 6 north of Bishop and segues onto NV 360 to US 95, another such route.   Coincidentally, this route is part of the shortest path from L.A. to the Boise/Treasure Valley section of Idaho.  And in the eastern part of the state, the N-S NHS corridor nominally along US 93 shifts to NV 318 and US 6 between Ash Springs and Ely -- again, the shortest route and one with similar facility standards to the longer US 93 routing.  The formulators of at least this region's share of NHS routes seem to be determined to provide route efficiency above other considerations, all else being roughly equal.

A good number of the four-lane corridors identified thus far are mainly in straight lines and have multiple route numbers along the way.  It makes sense, as the older route systems interconnected towns and facilities in a manner that made logistical (or political) sense back a long time ago.  Unfortunately, progress doesn't always follow the same paths.  Even on the East Coast, it is interesting how many local four-lane highways run perpendicular to the Interstate system between two or more seemingly unimportant destinations.  Many of these routes don't look like they belong on the map, but either there is sufficient traffic or politics to get them upgraded. 

Before I started down this path, I was looking as to whether STRAHNET routes would give a better view into the current status of the National Highway System.  My father was in the National Guard and Army Reserve for many years, so I was familiar with interesting routes used between Charleston, West Virginia and certain military bases (his unit was joint Army and Marines).  Anyhow, there are some major two-lane thoroughfares that deserve to be listed alongside major four-lane routes.  Might need to go back to STRAHNET to help flag some of these.

But I figured that about 25 years of progress (or lack of progress) should be sufficient to give us a new baseline.  The current overly simple methodology may have some real headaches in developing route lists for some of the states.

[Dirt Roads]

Alabama

Limited Access highways (over 20 miles)

• none

Multi-state routes (over 20 miles)

• Columbus to Phenix City to Opelika (US-280/US-431)
• Thomasville to Bainbridge to Dothan (US-84)

• Tuscaloosa to Columbus MS to Starkville to Winona to Greenville to Pine Bluff AR (US-82//US-65)
• Cullman to Muscle Shoals to Corinth MS to Collierville TN (AL-157//US-72)

• Florence to Lawrenceburg to Columbia TN (US-43)
• Huntsville to Fayetteville TN (US-231/US-431)
• Huntsville to Scottsboro to Kimball TN (US-72)

Through routes (over 20 miles)

• Dothan to Euphala to Phenix City (US-431)
• Dothan to Troy to Montgomery (US-231)
• Dothan to Enterprise to Andalusia to Georgiana (US-84)
• Opelika to Alexander City to Sylacauga to Homewood (US-280)
• Gadsden to Albertville/Guntersville to Huntsville (US-431)
• Decatur to Muscle Shoals (Alt US-72)
• Athens to Killen (US-72)

Loop routes (over 20 miles)

• Dothan Ross Clark Circle (US-84//US-231//US-431), needed for connectivity
• South Blvd/Eastern Blvd/Northern Blvd (US-80/AL-152//US-231/AL-152), needed for connectivity

Spur routes (over 20 miles)

• Satsuma to Jackson to Grove Hill to Thomasville (US-43)
• Montgomery to Selma (US-82)
• Selma to Demopolis to Cuba (US-82)
• Anniston to Gadsden (US-431)
• Huntsville to Arab (US-231)
• Decatur to Mouton to Russellville to Red Bay into Mississippi (AL-24//MS-76)

Not quite making the lists

• Montgomery to Selma to Demopolis to Cuba (US-82), disqualified around Selma
• Center Point to Pinson to Oneonta (AL-75)
• Anniston to Gadsden (US-431), through route not interconnected to I-759
• Fort Payne to Section (AL-35), not quite long enough

[Dirt Roads]

Mississippi

Limited Access highways (over 20 miles)

• none

Multi-state routes (over 20 miles)

• Tuscaloosa to Columbus to Starkville to Winona to Greenville to Pine Bluff AR (US-82//US-65)

• Cullman to Muscle Shoals to Corinth MS to Collierville TN (AL-157//US-72)
• Leland to Clarksdale to Memphis (US-61)

• Vicksburg to Natchez to Woodville to St. Francisville to Baton Rouge (US-61//US-84//US-61)
• Natchez to Ferriday to Winnsboro to Raysville (US-425)

• Moss Point to Meridien to West Point to Tupelo to Corinth to Henderson to Jackson (US-45//Alt US-45//US-45)

Through routes (over 20 miles)

• Moss Point to Lucedale to Waynesboro to Meridien (MS-63//MS-57//US-45)
• Gulfport to Hattiesburg (US-49)
• Biloxi to Saucier (MS-67)
• Hattiesburg to Columbia to Tylertown to McComb (US-98)
• Hattiesburg to Collins to Mendenhall to Richland (US-49)
• Natchez to Brookhaven to Collins to Laurel to Waynesboro to Alabama Line (US-84), spur east of US-45
• Batesville to Oxford to Pontotoc to Verona (US-278)

Spur routes (over 20 miles)

• Hattiesburg to Lucedale to Alabama Line (US-98)
• Meridien to House (MS-19)

Not quite making the lists

• Brooksville to Columbus to Aberdeen to Shannon (US-45), parallel to US-45A
• Pontotoc to Sherman (MS-9), too short, consider exemption as through route
• Shannon to Tupelo to Saltilo (US-45, Limited Access), almost long enough, consider exemption (if multiple designations available)
• Starkville to Alabama Line (US-82, Limited Access), not directly connected to an Interstate route

Note that the connecting routes in Alabama and Mississippi are amazingly well distributed over both of the states, respectively.

[Dirt Roads]

Tennessee

Limited Access highways (over 20 miles)

• Chattanooga to Signal Mountain to Soddy-Daisy to Dunlap (US-27//TN-111)
  
• Dyersburg to Troy (US-51)(future I-69)

Multi-state routes (over 20 miles)

• Florence AL to Lawrenceburg to Columbia TN (US-43)
• Huntsville to Fayetteville TN (US-231/US-431)
• Huntsville to Scottsboro to Kimball TN (US-72)
• Cullman to Muscle Shoals to Corinth MS to Collierville TN (AL-157//US-72)

• Leland to Clarksdale to Memphis (US-61)

• White Pine to Morristown to Middleboro to North Corbin (US-25E)

Through routes (over 20 miles)

• Bristol to Bluff City to Elizabethton (US-19//US-19W)
• Soddy-Daisy to Dayton to Spring City to Harriman (US-27)
• Tullahoma to McMinnville to Sparta (TN-55//US-70S)
• Murfreesboro to Woodbury to McMinnville (US-70S)
• Pelham to Winchester to Lawrenceburg to Selmer (US-64)
• Clarksville to Dover to Paris to McKenzie (US-79)
• Union City to Martin to McKenzie to Lexington (TN-22), spur south of I-40
• Jackson to Three Way to Milan to Martin (Byp US-45//US-45//US-45E)
• Three Way to Humboldt to Dyer to Kenton (US-45W)
• Jackson to Alamo to Dyersburg (US-412)
• Millington to Covington to Ripley to Dyersburg (US-51)
• Eads to Whiteville to Bolivar to Selmer (US-64)

Spur routes (over 20 miles)

• Mosheim to Greeneville to Jonesboro to Johnson City (US-321)
• Rockford to Maryville to Vonore to Madisonville (US-411)
• Eaton Crossroad to Lenoir City to Maryville to Townsend (US-311)
• Decatur to Athens to Etowah (TN-30), spur east/west of I-75
• Englewood to Etowah to Benton to Ocoee (US-411), spur north of Etowah
• Cleveland to Ocoee to Parksville (TN-40)
• Livingston to Cookeville to Sparta to Spencer (TN-111)
• Murfreesboro to Shelbyville (US-231)
• Shelbyville to Tullahoma to Winchester (Alt US-41)
• Hendersonville to Gallatin to Portland (TN-386//TN-109)
• Gilmore to Lexington to Darden (US-412)

Not quite making the lists

• Paul Barret Parkway (TN-385), too short, consider exemption
• Bill Morris Parkway (TN-385), too short, consider exemption
• Union City to Martin (TN-22//US-45E Limited Access), too short, consider exemption
• Goodlettsville to Hendersonville to Gallatin (TN-386), too short
• Mosheim to Greeneville to Jonesboro to Johnson City (US-321), not interconnected to I-26
• Newport to Caney Branch (US-321), too short
• Knoxville to New Market to Morristown (US-11E), too much parallel to I-40
• I-40 to Sevierville to Pigeon Forge to Gatlinburg (TN-66//US-441), not interconnected at Sevierville
• Knoxville to Sevierville (US-441), not interconnected at either end
• Millersville to Springfield (US-41), too short
• Pelham to Lawrenceburg to Bolivar to Eads/Memphis (US-64), zig-zag at Selmer

[Dirt Roads]

Kentucky

Limited Access highways (over 20 miles)

• Bert T. Combs Mountain Parkway (KY-9000), four lanes west of Campton
• Blue Grass Parkway (KY-9002)
• Cumberland Parkway (KY-9008)
• Audubon Parkway (KY-9005)
• Western Kentucky Parkway (KY-9001)

Multi-state routes (over 20 miles)

• Charleston to Logan to Williamson to Pikeville (US-119)

• Kingsport to Gate City to Big Stone Gap to Wise to Pikeville to Catlettsburg (US-23)

• White Pine to Morristown to Middleboro to North Corbin (US-25E)

• Henderson to Evansville (US-41), future I-69
• Bowling Green to Owensboro to Dale IN (Natcher Pkwy//US-231)

Through routes (over 20 miles)

• Water Gap to Combs to Manchester to London (KY-80//Hal Rogers Pkwy)
• Bowling Green to Russellville to Hopkinsville (US-68/KY-80)
• Mayfield to Paducah (US-45)

Spur routes (over 20 miles)

• Lexington to Paris to Millersburg (US-68)
• Frankfort to Versailles to Lexington (US-60)
• Frankfort to Lawrenceburg to Harrodsburg to Danville to Stanford (US-127//US-150)
• Elizabethtown to Radcliff to West Point to Bethany (US-31W)
• Bowling Green to Scottsville (US-231)
• Benton to Murray (US-641)
• Mayfield to Murray to Canton (KY-80//US-68/KY-80), spurs east/west of US-641

Not quite making the lists

• Portsmouth OH to South Shore to Ashland (US-23), parallel to US-52, congestion in Ashland
• John Y. Brown AA Highway (KY-9), mostly two lanes
• Ulysses to Inez to Auxier (KY-645//KY-3), parallel to US-23, short two-lane section at Auxier
• Hal Rogers Parkway (KY-9006) Limited Access, not through to I-75
• Bert T. Combs Mountain Parkway (KY-9009), only two lanes east of Campton
• New Circle Road (KY-4), not interconnected to I-64/I-75
• Lexington to Nicholasville to Bryantsville (US-68), not interconnected to I-64/I-75
• Frankfort to Versailles to Lexington (US-60), through route not interconnected to I-64/I-75
• Gene Snyder Freeway (KY-841), not long enough, consider exemption
• Elizabethtown to Radcliff to West Point to Bethany (US-31W), through route via KY-841
• Wendell Ford Expressway (US-60//US-60/US-231), not long enough, consider exemption
• Mayfield to Murray to Canton (KY-80//US-68/KY-80), not interconnected to I-69
• Mayfield to Murray to Hopkinsville to Bowling Green (KY-80//US-68/KY-80), short two-lane section

Kentucky brings up some paradoxes.  First, the parkway system development resulted in fewer through corridors over US Routes and State Routes.  Second, continuous long east/west corridors are wisely divided into shorter spur routes interconnecting to the north/south Interstates (including I-24).  Both require some rethinking about how the National Highway System actually works in real life.

One other quirk is how New Circle Road (KY-4) in Lexington is still not well connected to I-64 and I-75.  The short connection via Broadway Road (US-27/US-68) always was historically overcongested, as was the eastern connection using Winchester Road (US-60).  I doubt either qualify as a minimum average 45 mph over their section.

This completes almost all of the Southeast states and should represent enough to evaluate the types of issues facing the existing National Highway System.

[froggie]

Mississippi

Limited Access highways (over 20 miles)

• none

Unless I'm misunderstanding your criteria, US 82 from west of Starkville to the MS/AL line should qualify.  It's about 42 miles.  US 45 from Shannon (US 45A interchange) to Saltillo comes close at just under 20 miles.

[Dirt Roads]

Mississippi

Limited Access highways (over 20 miles)

• none

Unless I'm misunderstanding your criteria, US 82 from west of Starkville to the MS/AL line should qualify.  It's about 42 miles.  US 45 from Shannon (US 45A interchange) to Saltillo comes close at just under 20 miles.

<Deleted the incorrect response that referred to I-22>.

Oops.  Right now, only Limited Access corridors that are directly connected to Interstate highways are included.  But I should flag this under the "Not Quite Making the List" category in order to get some discussion about whether such section of highways should get preferential treatment over other four-lane sections.

[froggie]

^ In that case, you should also flag the US 45 segment I mentioned under "Not Quite Making the List", as it junctions with I-22 in Tupelo, but is just under 20 miles.

[Dirt Roads]

^ In that case, you should also flag the US 45 segment I mentioned under "Not Quite Making the List", as it junctions with I-22 in Tupelo, but is just under 20 miles.

Got it.  This is an example of another quandary, the spur route in the middle of a through route.  Let's say we have two new route designations (for simplicity, lets say Green Interstate Route and Green U.S. Route).  Thinking about something like a Green Spur I-22 (or Green 3di) multiplexed with a Green US-45, or change the whole corridor number that allows a new Green 2di and Green 2dUS with the same number (or something similar).  This example is a bit easier, since the existing U.S. Route could be truncated.  Trying to stick with signage approaches that AASHTO and the individual states could live with if funding for signage becomes available.

[hobsini2]

- US 68/KY 80 Hopkinsville-Mayfield
In Kentucky between Hopkinsville and Cadiz, US 68/KY 80, which does cross I-24, is already a 4 lane divided highway. West of Cadiz, the road is being upgrade (or already has) through the Land Between the Lakes area to Mayfield, stopping just a few miles short of I-69 on the Purchase Pkwy. Once the Mayfield Bypass, which according to KDOT is under construction, is completed, that section should be on the list.

[Dirt Roads]

- US 68/KY 80 Hopkinsville-Mayfield
In Kentucky between Hopkinsville and Cadiz, US 68/KY 80, which does cross I-24, is already a 4 lane divided highway. West of Cadiz, the road is being upgrade (or already has) through the Land Between the Lakes area to Mayfield, stopping just a few miles short of I-69 on the Purchase Pkwy. Once the Mayfield Bypass, which according to KDOT is under construction, is completed, that section should be on the list.

Understood.  It is interesting that the most recent NHS map I could find drops off the NHS route at Aurora and not Cadiz (and shows KY-80 to Mayfield as a MAP-21 principal arterial).  I've not fully grasped all of the changes since the ISTEA-1995 legislation, but I wonder if Aurora (where US-68 branches off) is a mistake.