The Pennsylvania Turnpike has an interesting history which affects its layout. It uses an abandoned railroad right of way. Where interstates typically emphasize straight lines or broad sweeping curves, railroads are much more concerned with limiting the gradients. That's how the Turnpike ended up with an idiotic looking route (as seen on a map) which avoids all potential steep grades.
IR 670 does the same thing through Columbus, Ohio. Its route follows the former train lines route. It parallels the remaining active line. So many curves!
Fun Fact: The highest point on the Interstate is in the Eisenhower Tunnels on I-70. The lowest point is not far from the eastern end of I-70...in a tunnel under Baltimore Harbor. So the highest and lowest points are both in Tunnels!
Another example of geography shaping highway infrastructure is the Lincoln Tunnel Helix. The Helix was built in 1937 and it is an oval-shaped 270-degree loop between the Palisades cliffs and the tunnel’s toll plaza on the NJ side of the Hudson River. The Helix was built in order to connect NJ Route 495 (in turn goes to the NJ Turnpike) at the top of the Palisades to the portals at the bottom, and to put things into perspective, are about 300 feet (90 m) high at Weehawken where the Lincoln Tunnel is! They originally thought about building a tunnel, but they realized it wasn't feasible and would disrupt the urban landscape above. They also had to make room for the toll plaza and merging lanes, hence why the Helix is quite the engineering feat. Though a just as impressive engineering feat that tackled the Palisades was the North Hudson County streetcars. They originated in the 1860s and lasted until the 1940s. The North Hudson County Railway was a complex streetcar network that connected Journal Square in Jersey City, Hoboken, Weehawken, and Union City. How did they get the streetcars down these dangerous cliffs to low-lying Hoboken and Weehawken by the Hudson River? By devising many engineering innovations from a huge and long elevated trestle, viaducts, funicular wagon lifts, and an elevator! The system included 12.75 miles (20.52 km) of at-grade and 1.25 miles (2.01 km) of elevated trackage!
Interstate 24 in Tennessee is another great example. It goes through a feature scientists have called a "clusterfuck" named Nashville. Then it goes up the cumberland plateau and down. This stretch is infamously dangerous, especially for truckers. Then you go through Chattanooga. So you have limited space to build highway because of the mountains and you have that big city traffic. And it goes up missionary ridge through Chattanooga which is also known to cause accidents.
A really good example of the “Interstates follow rivers” thing is I-40 through the Great Smokies in Western NC. The mountains there are the steepest and most solid they are at any point in the Appalachians, and so the road ended up following a narrow ravine cut by the Pigeon River. The road looks pretty ridiculous in this stretch and has been closed numerous times due to rockslides.
Geography has also shaped transit lines around the world. In Chongqing for example, they have elevated lines like the Line 2 monorail! Chongqing is a huge densely populated but mountainous city with multiple river valleys, so using monorails leverages the ability to negotiate steep grades and tight curves with rapid transit capacity! Chongqing's Line 2 is famous for Liziba station, which is located within an apartment complex! The apartment complex was built with the station, rather than before! It's transit-oriented development to the max! People may think living in the apartments is constantly noisy, but the station uses specialized noise reduction equipment to isolate station noise from the surrounding residences! Another example is the Wuppertal Schwebebahn in Germany, which is a suspension railway. Wuppertal is located in a river valley (that's what Wuppertal means; Wupper Valley), and because of steep slopes, the original towns that now makes up Wuppertal expanded lengthwise (resulting in the thin shape of Wuppertal today). It wasn't suitable to build a tram nor a subway, so as a way to both unify the valley and find a place for transit to solve congestion, they built a suspended monorail that followed the Wupper River
California has plenty of examples. U.S. 50 for instance was slated to be a full freeway from Sacramento to South Lake Tahoe. The roadway was never completed due to the geography. The original alignment for I-280 actually intended to bypass Downtown San Francisco to the West parallel to 19th Ave. The demolition price tag wasn’t worth the effort.
If the state highway department even thought of air rights development they could have recouped the demolition costs. But then the highway would be a spur to the Golden Gate Bridge because the Embarcadero Freeway would never have been extended.
@edwardmiessner6502 You are a bit confused. The Embarcadero and 19th Ave are on completely different sides of the city. They never interact. The Embarcadero Freeway was designated as 480, not 280. What good would it do to have the air rights in the Sunset? 99% of the buildings are under 3 stories.
I-24's path through southern TN is completely dependent on being able to weave through plateaus and ridges. Only a 2-3 mile wide gap in Lookout Mountain and Signal Mountain controls 99% of any traffic heading west from Chattanooga. Then there is the narrow canyon between the split from I-59 and Nickajack Lake. The last tricky portion is crossing the Cumberland Plateau at Monteagle.
One thing about that fall line across New England. In the winter time, sometimes there can be a temperature difference between the lower elevation along the coast, and it will be rain there, but go towards the interior and that modest elevation gain will put you into an area that it's snowing.
A huge one is the Great Lakes. Specifically Lake Michigan. You see the issues getting east-west across Wisconsin because all the major highways go south through Chicago to go around the lake. I90 and I94 both have a NW to SE path across the state from Eau Claire/Tomah to Madison. The only real freeway/expressway that connects across the state East West is WI-29.
The most "geographic" highways I've driven here in Canada include the Trans-Canada Highway (BC 1) through Rogers Pass and the Coquihalla Highway (BC 5). The Coquihalla looks and feels a lot like I-70, including insane winter conditions.
3:10 -- Lincoln, NE was very much laid out on/near Salt Creek, as the salt obtainable from the creek was a key commodity that attracted settlers to the area. However, the original key streets are on a north/south/east/west surveyed grid, not aligned with the river (or railroads) as you see in other cities. Further west in the state, I-80 follows the Oregon Trail route, which comes up from Kansas and meets the Platte River near Kearney. It's part of the common evolutionary path of many US roadway corridors: Animal track -> Native American trail -> wagon route -> railroad -> car road / highway -> Interstate. Going west from Glenwood Canyon, Interstate 70 reaches its final obstacle: the San Rafael Swell in Utah. It's known as the part of the Interstate system with the longest gap (110 mi) between gas/services, because it took a new route that wasn't covered by previous US highways and didn't go near any settlements. While it seemed pointless/laughable to build a freeway through there, it served to connect Denver with I-15, Las Vegas, and ultimately Southern California.
You should touch on Hwy 167 in Batesville and Southside Arkansas. The terrain is fairly hilly but not horrible..... until this one spot right between the towns where the otherwise mainly straight roadway curves to the east and then SHARPLY back to the west and then realigns with a straight shot
The taconic parkway is another interesting one - the highway took over 40 years to build and you can see the evolution of technology throughout. In the 1940s, the highway entered a super hilly and wooded area. The highway follows many valleys throughout this section around and north of Tomkins corners. For many of us NYers, the highway is a normal occurrence but to out of staters people driving 70mph through many tight curves scares them lol
I'm surprised Louisiana was left out of this considering the longest bridges on the interstate system are in Louisiana which include I-10 and I-55 as they have to cross extensive swamp
I think it's quite interesting that there actually those long stretches of straight highways. In Germany (where I'm from) this would actually be illegal, if there would actually be the space for that. As far as I know any road has to have a radius of at least 20km (12,4274 miles), so the drivers won't get bored or tired from driving. Of course, there are still a few a few straight stretches of road that are completely straight, e.g. the A66 highway near Frankfurt a.M. that was build on the same route as an old Roman road. But at least the routes always exisited prior to this rule/law
I 55 in Mississippi follows the outer edge of the MS Delta, going through the forests instead of the flat Delta. It parallels US 51. I assume they did this as US 51 was the direct route b/w Memphis, Jackson , and NOLA, and building 55 closer to those US 51 towns rather than the Delta helps ease traffic.
Very nice! You taught some geography as well, such as the interrelationship between physical and cultural geography as location factors for populations and routes.
Years ago I was watching a Nat Geo show about interstates. The companies that built I-70 west of Denver were charged/fined a set amount of money for each tree they cut down. The fine varied by what kind of tree it was and possibly by age, but I could be wrong about that.
Both. The routes of many of the original Eisenhower Interstate System routes were affected by whom the most influential congress members were in the 1950's. US routes tend to follow the original auto club trails from which they are descended. Over the years, state DOT's have straightened the more dangerous mountain passes out west...which were built where they were originally to save money and connect population centers.
Not always. Sometimes there's compromises between using a flat / featureless route with lower population for the sake of shorterning distances and ensuring population centers are actually served. Balancing different priorities in linear transportation network alignments is a pretty rigorous process. Construction expense, while important, often isn't the tie-breaker between competing alternatives.
I-90 from Boston to Buffalo is not exactly a straight shot. The New York State Thruway once it crosses the Tappan Zee and meets NJ 17, curves north direct to Albany which it curves around and heads around Schenectady and then follows the Mohawk River to Utica, and then heads basically straight to Buffalo. But the Massachusetts Turnpike section of I-90 has to struggle with the Wachusetts and Berkshire Hills mountain ranges so it has quite a curvy alignment to the NY state line, then the Thruway Authority takes over and sends it almost straight to the main Thruway. That's the main interstate travel but I-90 leaves the Turnpike west of the state line to make an excursion through Albany and meet the Thruway where I-87 peels off of it.
Worth checking out is with 21st century engineering and hilariously steel and cement overproduction massively deflating their prices (even then I'm sure the budget was massive) China has literally build highways over Moutains. In Japan, China, and Europe too the extremely mild grades and wide turns needed for high speed rail lead to long tunnels through mountainous regions as well.
The northwest ordinance and the nature of property lines therefore is why the roads are laid out in the one mile by one mile grid. Notice, everywhere in the lower 48 outside of the original colonies, parts of the deep south, and Louisiana follow the great survey of township, range lines
IR 77 through Virginia? has a great spot where you go through the side of the mountain with it on both sides. I suppose you call the remaining rock on the east side pinnacles? Also, it offers a great view of the valley whether clear day or night!
While visiting my Grammaw in Wytheville in the mid to late 1960s, my dad and I used to regularly hang out on the side of the county road (off of VA 717) above the Big Walker Mountain Tunnel construction site and watch them blast and haul off the rubble.
I feel like such a brat saying it correctly, basically everyone says apple ay shu, and I really prefer it that way. It's how I've said it my entire life
@@BeaverGeography Thanks for replying! My family is largely from southwestern Virginia and was VERY generous with giving people lots of grief for that particular mispronunciation. I suppose I should let it slide since they're all dead now. That being duly noted, pronouncing place names as the locals do is not at all bratty -- it's simply respectful. Have a great holiday weekend and a prosperous new year!
