Most dramatic contrasts on a single route in a single state

[sparker]

Another good one is CA 78, which starts out as a major commuter freeway at I-5 between Carlsbad and Oceanside, becomes a series of city streets in Escondido, a rural highway through farm and ranch land out to Ramona, a mountain highway through Julian and continuing as such into the Anza-Borrego Park, where the surroundings rapidly change to desert.  From there it remains a desert highway; first as a 2-lane descent from the park to CA 86, then an expressway and conventional divided highway multiplexed with 86, then as a 2-lane expressway -- with occasional interchanges -- out to CA 111, then as a rural highway across Imperial Valley farmlands before abruptly changing to a desert arterial plowing through sand dunes near Glamis, then a typical desert 2-lane road gradually turning northward toward the Palo Verde Valley, at which point it becomes an archetypal farmland highway to its terminus at I-10 near Blythe.  And it manages to essentially cross the entire state in the process; it runs adjacent to the AZ state line along the Colorado River just south of Palo Verde.  Very few CA state highways have this type of variance in both population and territory served.

[DandyDan]

I have to believe in Iowa, it's US 218. It bounces around from 4 lane urban arterial to expressway to freeway, including overlapping I-380, to rural 2-lane highway. The transition from one road type to another is often swift.

[ethanhopkin14]

US-67 in Texas goes from being a rural 2-lane road in West Texas to being multiplexed with the busy I-35E and I-30 freeways in Dallas.

LA-1 in Louisiana is a rural 2-lane road in most of the state, but is one of the main north-south arteries in Shreveport.

Also SH 114.  It "enters" Texas (from New Mexico 114) as a dusty panhandle two lane road, and with the help of some multiplexes and the Lubbock area, it graduates to a 4 lane and expressway highway, then it goes back to a 2 lane highway.  When it's all said and done, it finishes it's life as the John Carpenter Freeway and a major freeway link between Dallas and Ft Worth.

Also US 90.  From it's western terminus in Van Horn to Marfa, it's a West Texas lonely 2 lane highway that you could literally lay down in the middle of for several minutes without feeling like you would get flattened.  When it reaches San Antonio, it is a full fledged interstate grade freeway.

US-90 in Texas:

https://www.google.com/maps/@30.9236234,-104.809291,3a,60y,178.34h,78.94t/data=!3m6!1e1!3m4!1sllNWs81CRl8v7OwA5kbOCA!2e0!7i13312!8i6656

https://www.google.com/maps/@29.404212,-98.5525207,3a,75y,103.02h,88.71t/data=!3m6!1e1!3m4!1sXUXXJW9Y6oIqOaodRpYrIg!2e0!7i16384!8i8192

[Rothman]

In Massachusetts, probably MA 2.

MA 2 is still major in western Massachusetts, even though it's a surface road. What about MA 140? (I briefly considered 57 and 79, but they're minor freeways, making the contrast less.)

MA 9. It's relatively unimportant in western Mass, but east of Worcester is a 4-6 lane roadway all the way into Boston.

Pfft.  MA-9 is just as "major" as MA-2 is in western MA, connecting Amherst/Hadley/Northampton to Dalton/Pittsfield through the hilltowns.

MA-2 is a large, limited access freeway in eastern MA that eventually becomes a dinky rural road, especially its Taconic Trail section.  That's a wider spectum than MA-9.

[jakeroot]

US 12 in WA - From the tide flats of the Pacific Ocean, through the western steppe, through the south end of the Puget Sound Basin, over the Cascade mountains, then through the high desert of Washington, and then into the fertile valleys if Idaho.  From one-way couplets at US 101, to rural expressway, to 2-lane road, to 6 Lane Interstate Freeway, to 2-lane road again, more Freeway, 2-lane road, and more couplets.

This is definitely a good one. WA-240 might also be a contender. Totally dead through the deserts of Eastern WA, before becoming a major freeway through Richland and Kennewick. Goes from 2600 AADT to 76000 AADT.

[Sctvhound]

In SC: SC 61. Goes from a pretty non-descript 2 lane road, starting at just 850 AADT in Bamberg County, not connecting very much except for an I-95 exit, then goes up to 3K in Colleton County, goes through Dorchester County serving some of Charleston's exurban suburbs as a 2-lane, then connects the plantations (Magnolia Plantation, Drayton Hall, and Middleton Place) as a crowded 2-lane strip.

Then you get into West Ashley and it becomes a major arterial, peaking at over 50K AADT just west of downtown Charleston.

US 52 is another one. In about 10 miles it goes from a little-used, forgotten artery through the neck area of Charleston, to being a major connection for North Charleston's shopping. Once you get past Moncks Corner, it is a little-used mostly local route. But south of there it is one of the major highways in the region.

[Road Hog]

SH 121 in Texas starts out as a major freeway in NE Fort Worth, continues northeast as the frontage roads of the Sam Rayburn Tollway, multiplexes with US 75 through McKinney and winds up as a pissant road with no shoulders teeing out with an FM road between Bonham and Ivanhoe.

[Max Rockatansky]

For New Mexico I'll give a plug for US 70.  US 70 starts as a two lane highway, multiplexes I-10, is a major surface street in Las Cruces, is a one of the few non-Interstate Freeways in the State east of Las Cruces, passes by a National Park in White Sands, crosses the Sierra Blanca Mountains, and ends leaving the state in plains east of Roswell. 

[Gnutella]

Driving I-75 in Georgia is pretty interesting.


Florida state line (MM 0) to Tifton (MM 63): Flat and swampy

Tifton (MM 63) to Unadilla (MM 122): Rolling hills and farmland

Unadilla (MM 122) to Locust Grove (MM 212): Verdant with choppy terrain

Locust Grove (MM 212) to Kennesaw (MM 269): Urban chaos

Kennesaw (MM 269) to Tennessee state line (MM 355): Mountainous

[KCRoadFan]

Driving I-75 in Georgia is pretty interesting.


Florida state line (MM 0) to Tifton (MM 63): Flat and swampy

Tifton (MM 63) to Unadilla (MM 122): Rolling hills and farmland

Unadilla (MM 122) to Locust Grove (MM 212): Verdant with choppy terrain

Locust Grove (MM 212) to Kennesaw (MM 269): Urban chaos

Kennesaw (MM 269) to Tennessee state line (MM 355): Mountainous

And I'm guessing the common thread that ties all these sections together is Waffle Houses at almost every major exit. At least, that's what I've heard about Georgia.

[Gnutella]

Driving I-75 in Georgia is pretty interesting.


Florida state line (MM 0) to Tifton (MM 63): Flat and swampy

Tifton (MM 63) to Unadilla (MM 122): Rolling hills and farmland

Unadilla (MM 122) to Locust Grove (MM 212): Verdant with choppy terrain

Locust Grove (MM 212) to Kennesaw (MM 269): Urban chaos

Kennesaw (MM 269) to Tennessee state line (MM 355): Mountainous

And I'm guessing the common thread that ties all these sections together is Waffle Houses at almost every major exit. At least, that's what I've heard about Georgia.

Some busy interchanges even have Waffle Houses on both sides.

[Kulerage]

For North Carolina I nominate US 64. When you run for 604 miles, you're bound to get some variety.

In the western mountains alone, you can go from occasional expressway with many roads around you to extremely sparsely-populated areas where you're down to undivided two lane road. Things pick up a bit around I-26, and we begin to reach the peak east of Asheboro, where we get non-stop expressway until US 1. Here we join interstates, and even get a Future I-87 corridor designated along the road until Williamston, where things cool down quickly. Now you're going through swampy coastal areas where we're back down to 2 lanes and there's virtually no civilization outside of some small towns. Even it's eastern terminus is a pretty small town.

[CtrlAltDel]

I nominate CA-23. It's not an especially long route, less than 40 miles, but it does go from a winding two-lane road in the Santa Monica mountains to a six-lane freeway before returning to two lanes to travel through farm country.

[epzik8]

I-70 in Maryland somewhat. Three to two lanes, plateau to mountains.

[Mccojm]

Some examples of ny routes on Long Island

NY-27:
Urban expressway at interchange with I-278 Gowanas Expwy in Brooklyn to rural 2 lane road with dead end loop around at montauk point light house some 120 miles to the East.

NY-25:
Queensboro bridge in Manhattan as an urban Hwy and terminates as a quiet rural 2 lane road in orient point at ferry terminal for the orient- new London ferry.

[hbelkins]

So, are we talking about scenery and terrain, or type of road?

Because if we're talking about the former, I'm changing my Kentucky example from US 60 to KY 80. Starts in the Purchase area, crosses the two big lakes in the western part of the state, runs through the Pennyroyal (Pennyrile) region, skirts the Outer Bluegrass and the Knobs, and then becomes very mountainous.

[JayhawkCO]

So, are we talking about scenery and terrain, or type of road?

Because if we're talking about the former, I'm changing my Kentucky example from US 60 to KY 80. Starts in the Purchase area, crosses the two big lakes in the western part of the state, runs through the Pennyroyal (Pennyrile) region, skirts the Outer Bluegrass and the Knobs, and then becomes very mountainous.

For me, I take it as a combination of both.  My selection for my state (I-70) obviously gains some lanes in Denver and a bunch of congestion compared to the plains to the east, but it's also stick straight for portions out east and the opposite thereof for most of the western portions.  I think some states that don't vary that much geographically would need to stick to more "road-specific" criteria.

Chris

[Kulerage]

So, are we talking about scenery and terrain, or type of road?

Because if we're talking about the former, I'm changing my Kentucky example from US 60 to KY 80. Starts in the Purchase area, crosses the two big lakes in the western part of the state, runs through the Pennyroyal (Pennyrile) region, skirts the Outer Bluegrass and the Knobs, and then becomes very mountainous.

I also took it as both.

[Eth]

For Georgia, I submit US 19:

• Mountain switchbacks near the Appalachian Trail
• Major commuter freeway through the north Atlanta suburbs
• The heart of midtown Atlanta
• Two-lane minor artery near the airport
• Generic suburban sprawl on the south side
• Small-town Main Street in west central Georgia
• Freeway again, but for a much smaller city
• Rural expressway bound for Florida

[Stephane Dumas]

Can we add provinces? I'd nominate 401 in Ontario. 4 lane rural freeway outside of Windsor to however the hell many lanes in Toronto.

In Quebec, PQ-138 is a two-lane road but became a crowded arterial at Chateaugay, a freeway spanning the St.Lawrence River, a important street in Montreal and Trois-Rivieres, a big throughfare east of Quebec City to Ste-Anne-de-Beaupré and main road to Charlevoix area and the North Shore. 

[StogieGuy7]

Numerous contenders in my mind, but I'll stick with major routes (out of laziness) that have huge contrasts. 

First one that comes to mind is I-70 across Colorado: goes from the plains near Burlington, through the urban sprawl of metro Denver, then up over (well, through) the Continental Divide with high mountain scenery, and then wanders slowly downward through Glenwood Canyon and into the Colorado Plateau (desert/red rock) scenery of the Western Slope.  Pretty major contrast there.

Two others that are pretty obvious if you think about it:

Texas and I-10: you go from tall pine forests, swampland and the deep south/Gulf Coast area all the way to the basin and range country of the Chihuahuan Desert in far west Texas.  That's a major contrast, with large cities like Houston/San Antonio and the Texas hill country in between.

Finally California and either I-5 or US-101.  I-5 from San Ysidro and the border with semi arid desert scenery, the LA Basin, the mountains, then through the flatness of the Central Valley, into the forested mountains north of Redding and by Mount Shasta.  US-101 was better before it was truncated, but still LA to the redwood forests of Del Norte County with the Bay Area and another 700 miles in between.  For a shorter distance, I-80 is another candidate - contrast Truckee and Donner Summit with the Bay Bridge. 

But most states will feature some contrasts from one end to another.

[ethanhopkin14]

Texas and I-10: you go from tall pine forests, swampland and the deep south/Gulf Coast area all the way to the basin and range country of the Chihuahuan Desert in far west Texas.  That's a major contrast, with large cities like Houston/San Antonio and the Texas hill country in between.

Agreed, also being in west Texas with very low traffic counts east of the I-20 split to Houston and one of the widest freeways in the world. 

[Occidental Tourist]

I vote for CA 41.  Has contrasting features, starting as a two-lane at the beach, turning into a freeway, and then back into a two-lane when it ends in Yosemite.  It sees a beach climate, a foothill climate, the semi-desert climate of the southern Central Valley, and then snow and other mountain weather when it gets into the eastern part of the Sierras.

[kurumi]

I-95 in CT is a good choice, but I'll nominate CT 20. From small to big:

"You probably want the other Route 20", Colebrook: https://goo.gl/maps/35GCAJiJh2esDY73A

Quaint New England charm, Riverton: https://goo.gl/maps/4sCfstoRsA9pgYgB8

The lowest AADT of any state route intersection in CT, Hartland: https://goo.gl/maps/VunfKTmby8v52N3c9 (old CT 20 continues straight)

Google Street View just straight up stopped filming here, Hartland: https://goo.gl/maps/PmBa1aN1Y1KccuMy6

State's largest Sine Salad, Granby: https://goo.gl/maps/j4oZTKqGRe2xVNxK7

4-lane divided highway, E. Granby: https://goo.gl/maps/RUM62VgJdvbLAy9U6

Airport: https://goo.gl/maps/nde3YKLYpJC36CEc9

Bigshot freeway: https://goo.gl/maps/HCFogsFtckpJicU56