The flattest highways

[Max Rockatansky]

In honor of Illinois 1 being an award winning flat highway I thought that I pose a question to the group.  What is the flattest signed highway in your area or state?  Near me there are couple notably flat highway but the winner in California is likely CA 43.  CA 43 essentially compromised of largely rail frontage roads along the BNSF line running east of the Tulare Lake bed.  There are few hills of note and very little terrain variation along CA 43.  Honorable mentions go to CA 137 and CA 45. 

[TheHighwayMan3561]

Minnesota is right up there with Illinois in the rankings. Some of the greatest hits:

MN 220
US 75
MN 210 from the border to I-94
MN 1 west of US 71
MN 11, even the pretty parts along the Rainy

[7/8]

There's quite a few flat (and straight) highways in southwestern Ontario. I think Highway 77 would be a strong candidate for flattest. It's entirely in Essex County which seems especially flat.

[formulanone]

Alabama 14 in from Selma to Prattville is quite flat, though the road curves a bit.

US 72 Alternate is flatter than its non-Alternate cousin.

The southwestern sections of I-59/20 (SW of Tuscaloosa) get a little flat and dull.

All in all, it's not as flat as the southern halves of Florida or Louisiana, but there's only a few sections without much elevation changes.

[pianocello]

I'm sure Florida is teeming with flat highways, especially near the coasts. For a cross-peninsular route, though, I nominate SR 24, particularly the section west of Bronson. It helps to be following the alignment of a former railroad for nearly its entire length.

[MikieTimT]

In Arkansas, US-65 SE of Pine Bluff.  Levees and bridges might well be the only thing you'd need to downshift a bicycle on between Pine Bluff and the Louisiana border.

[triplemultiplex]

I-29, North Dakota!
Where the overpasses are the highest point for a hundred miles in every direction.

Doesn't get much flatter than the plain from Glacial Lake Agassiz.

[MATraveler128]

For Massachusetts, I'll say MA 88 from I-195 in Westport to Horseneck Beach as well as some of the routes on Cape Cod.

[CoreySamson]

Coastal and southern Texas is gold for flat highways. TX 35 is 200 miles long and the highest it gets is on the Corpus Christi Harbor bridge. I would also happen to guess that I-2 is the flattest interstate route. It's actually difficult to think of a route around here that actually rises or falls more than a few feet.

[thspfc]

WI's flattest highway of major distance has to be WI-73.

[Bruce]

My guess for Western WA is either WA 546 or WA 544, given they travel across the Fraser Lowlands and don't head up into the hills.

WA 281 should win for the state, given it seems to only gain about 100 feet in elevation and only has to dip to cross one shallow canal.

[Crown Victoria]

My guesses for PA would be:

-I-95, running through the Delaware Valley (and the western fringe of the Atlantic Coastal Plain, near the fall line) for its entire length in PA
-I-90, US 20, and PA 5, running either where the bottom of Lake Erie once was or along the ancient shorelines. 

[JayhawkCO]

CO116 in the southeastern part of the state I recall not even having a bump.

[Road Hog]

I-55 has got to be the flattest interstate. It parallels the Mississippi River from New Orleans to St. Louis and then traverses Illinois, which is ... you know ...

The portion in Mississippi that diverts a bit from the river might have a little bit of slope here and there. And I know there are segments in Missouri south of the Cape that have a few rock cuts that aren't completely flat.

[SectorZ]

For Massachusetts, I'll say MA 88 from I-195 in Westport to Horseneck Beach as well as some of the routes on Cape Cod.

I know they're shorter, but 129A and 286 would each give 88 a run for its money. 240 is also probably just a 30-40' uphill from US 6 to I-195 in its one mile.

[SD Mapman]

For Wyoming, probably WY 73 near Bairoil.
For South Dakota, probably SD 224 near Alpena.

[MATraveler128]

I'll go ahead and say that New Hampshire is probably NH 286 and NH 1B.

[fillup420]

NC 12

The largest elevation change is most likely on the new Bonner bridge

[Dirt Roads]

NC 12

The largest elevation change is most likely on the new Bonner bridge

And the two ferry boats.    (Actually, there are a few new bridges between the Basnight Bridge (Bonner replacement) and Hatteras that add some elevation).

[plain]

If we're talking significant length, US 13 and US 258 might be VA's flattest.

Hell nationally US 13 is probably up there as well.

[Dirt Roads]

If we're talking significant length, US 13 and US 258 might be VA's flattest.

Hell nationally US 13 is probably up there as well.

Definitely not Virginia's flattest, but I would think that US-17 south of Tidewater all the way to Punta Gorda takes the [pan]cake.  For that matter, US-17 isn't very hilly south of Fredericksburg.

[SkyPesos]

For Ohio, all 2di that pass through the southeastern portion of the state (dividing line is roughly an arc between Cincinnati and Youngstown that passes just south and east of Columbus) have significant non-flat portions. So for 2di, that eliminates all 2di except I-90 for flatness.

[ethanhopkin14]

Coastal and southern Texas is gold for flat highways. TX 35 is 200 miles long and the highest it gets is on the Corpus Christi Harbor bridge. I would also happen to guess that I-2 is the flattest interstate route. It's actually difficult to think of a route around here that actually rises or falls more than a few feet.

I would say US-77 from south of I-37 to Harlingen takes the cake because it is long/flat and straight.  Maybe it's not the flattest in the state because it may have a rise and fall here and there, but on average it is extremely flat.  SH-361 on Mustang Island and SH-87 on the Bolivar Peninsula are probably the flattest but are not as long. 

Aside from the over/underpasses, Katy Freeway is pretty flat.

This being said, all you non-Texans out there, this is not an invitation for everyone not from here to talk about how flat Texas is.   It mostly is not, but we do have some coastal plains that are very flat. 

[SkyPesos]

This being said, all you non-Texans out there, this is not an invitation for everyone not from here to talk about how flat Texas is.   It mostly is not, but we do have some coastal plains that are very flat.

Texas doesn't have a Lord Carhorn uploading Youtube videos of flat roads and saying it's not flat, so no.

[Max Rockatansky]

This being said, all you non-Texans out there, this is not an invitation for everyone not from here to talk about how flat Texas is.   It mostly is not, but we do have some coastal plains that are very flat.

Texas doesn't have a Lord Carhorn uploading Youtube videos of flat roads and saying it's not flat, so no.

Western Texas definitely isn't flat, the Guadalupe Mountains come to mind as surprisingly high and varied.  The Big Bend region has a lot going on terrain variance. 

That said, it would be absolutely horrid to have a Carhorn variant out there with stereotypical Texas bravado mixed in.