I believe that 70 in Co is the highest Interstate, but what's the lowest one?
The highest point on the Interstate Highway System is at the Eisenhower Tunnel on Interstate 70 in the Rocky Mountains of Colorado, at the Continental Divide (elev. 11,158 ft/3,401 m).
The lowest point on land is on Interstate 8 at the New River near Seeley, California (elev. -52 ft/−16 m).
The lowest point under water is on Interstate 95 in the Fort McHenry Tunnel under the Inner Harbor in Baltimore, Maryland (elev. -107 ft/−33 m).
Source: Wikipedia
Interstate 8 at the New River near Seeley, California
What's the Highest and Lowest Interstate in each state? :)
Highest Interstate east of the Mississippi is the I-80 in Pennsylvania, if I remember correctly.
Might the upgrading of NY-17 into I-86 cause the I-86 to be higher?
In Georgia, the highest numbered interstate is I-985, which connects I-85 with Gainesville (GA).
The lowest numbered interstate in the aforementioned state is I-16, which connects Macon and Savannah.
Be well,
Bryant
California's highest is probably Interstate 80 over the Donner pass.
that is correct. about 3000 feet higher than I-5 and I-15 over the San Gabriels, and I-8 near Alpine.
now if they ever make an interstate out of US-395, then Conway Summit will be the highest.
Oh, the question is highest in terms of elevation, not interstate highway number. My bad. :-D
Be well,
Quote from: Chris on January 22, 2009, 09:30:12 AM
Highest Interstate east of the Mississippi is the I-80 in Pennsylvania, if I remember correctly.
Might the upgrading of NY-17 into I-86 cause the I-86 to be higher?
I-80 in PA is higher than I-93 in Northern New Hampshire or I-91 in Northern Vermont?
If so I'm shocked.
Otherwise this sign is wrong:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.northeastroads.com%2Fpennsylvania080%2Fi-080_wb_exit_111_01.jpg&hash=a33f7a6729449cd0b38abc1d43cdae6be201edfa)
edit: it's only about I-80. Perhaps other Interstates are higher...
Quote from: Freewayjim on January 23, 2009, 04:38:10 PM
I-80 in PA is higher than I-93 in Northern New Hampshire or I-91 in Northern Vermont?
Poking around Google Earth indicates:
- I-87 getting upt to 1300 feet or so at a couple spots in the Adirondacks, but that's it.
- I-89 peaking at about 1700 feet south of Northfield, VT
- I-91 peaking at about 1900 feet north of Sheffield, VT
- I-93 peaking just shy of 2000 feet in Franconia Notch
- NY-17/I-86 peaking just above 2100 feet west of Karrdale
So that neck of the woods doesn't beat I-80.
However, I-64 gets up to about 2450 feet at the VA/WV line, so we
can prove by counterexample that I-80 there is not the highest point on
any interstate east of the Mississippi.
As to whether that one on I-64 is the highest... I don't know. I'm not running my mouse pointer along every interstate in the Appalcacians.
In Oregon, the high point would have to be Interstate 84 near Meacham, Oregon, if I'm not mistaken. In Washington, it's Interstate 90 over Snoqualmie. Though I believe Interstate 90 over Lookout Pass on the Idaho/Montana border has them all beat for the Northwest.
Lowest point is obviously on I-5 somewhere in the valleys, as evidenced by the flooding the past couple winters.
-Alex (Tarkus)
I've been over that pass on I-64 several times and don't remember there being any sort of a sign saying it was the highest... Whoops... nevermind, wrong interstate. :pan:
(//www.aaroads.com/forum_images/northwest/i-090_snoqualmie_pass.jpg)
Interstate 90 eastbound at Snoqualmine Pass.
(//www.aaroads.com/forum_images/northeast/i-091_highest_elevation.jpg) (//www.aaroads.com/forum_images/northeast/i-091_highest_elevation.jpg)
Interstate 91 in northeastern Vermont.
Quote from: Duke87 on January 23, 2009, 08:31:49 PM
Quote from: Freewayjim on January 23, 2009, 04:38:10 PM
I-80 in PA is higher than I-93 in Northern New Hampshire or I-91 in Northern Vermont?
Poking around Google Earth indicates:
- I-87 getting upt to 1300 feet or so at a couple spots in the Adirondacks, but that's it.
- I-89 peaking at about 1700 feet south of Northfield, VT
- I-91 peaking at about 1900 feet north of Sheffield, VT
- I-93 peaking just shy of 2000 feet in Franconia Notch
- NY-17/I-86 peaking just above 2100 feet west of Karrdale
So that neck of the woods doesn't beat I-80.
However, I-64 gets up to about 2450 feet at the VA/WV line, so we can prove by counterexample that I-80 there is not the highest point on any interstate east of the Mississippi.
As to whether that one on I-64 is the highest... I don't know. I'm not running my mouse pointer along every interstate in the Appalcacians.
I-68's highest point is around 2800 feet, at Keyser's Ridge.
(//www.aaroads.com/forum_images/northwest/i-090_lookout_pass.jpg) (//www.aaroads.com/forum_images/northwest/i-090_lookout_pass.jpg)
Interstate 90 west at Lookout Pass (ID/MT border)
is that the highest point on the 90?
*shrug*, you should know, considering that you've done most of it :-D
all of it. when I was doing my research for my Wisconsin trip a few months ago, I realized I had done it all in Wisconsin, as well as the Illy toll road section, and therefore I had clinched it.
so I clinched 43 while I was up there instead.
What's the lowest interstate in WA?
Highest: I-90 at Snoqualmie Pass
Quote from: ComputerGuy on January 24, 2009, 01:00:49 PM
What's the lowest interstate in WA?
Highest: I-90 at Snoqualmie Pass
Probably I-90 across across the Lake Washington Bridge.
Wonder what they are in Kansas? :-P
Quote from: voyager on January 29, 2009, 04:47:14 AM
Wonder what they are in Kansas? :-P
low in the east, high in the west. Kansas rises steadily.
I'm figuring the highest point is I-70 near the Colorado border, and the lowest is somewhere in the KC area.
Highest point in the Nation? I-70 (Eisenhower Tunnel in Colorado)
Lowest point in the Nation? My guess is I-8 in the Imperial Valley, California.
I always wondered why American Interstates are much higher in altitude than in Europe, considering the Alps are about the same height as the Rocky Mountains (although on a much smaller scale ofcourse).
The highest in the Alps are around 4,200 feet (Brennerpass I think). Some Spanish freeways are a bit higher, tipping 4,600 feet.
Maybe Alpine valleys are lower, and allow a freeway to pass at lower altitudes. Perhaps it's also because we tend to have somewhat more/longer tunnels. The Gotthard tunnel in Switzerland is 10 miles long and replaces a 7,800 feet mountain pass above it.
The highest freeway-grade roads are in Bolivia, I noticed some La Paz freeway-like roads are at 13,000+ feet.
Quote from: Chris on January 29, 2009, 09:28:22 AM
I always wondered why American Interstates are much higher in altitude than in Europe, considering the Alps are about the same height as the Rocky Mountains (although on a much smaller scale ofcourse).
The highest in the Alps are around 4,200 feet (Brennerpass I think). Some Spanish freeways are a bit higher, tipping 4,600 feet.
Maybe Alpine valleys are lower, and allow a freeway to pass at lower altitudes. Perhaps it's also because we tend to have somewhat more/longer tunnels. The Gotthard tunnel in Switzerland is 10 miles long and replaces a 7,800 feet mountain pass above it.
Consider the surrounding geography. Denver is already at 5280 feet, so the Eisenhower Tunnel is really only about 6000 feet above the baseline of the mountains.
This applies elsewhere, too. The Rockies are quite on the interior of the continent, whereas the Alps are, in general, much closer to the sea. This makes a climb equally high into the Alps much steeper, which would make altitude sickness a problem if the roads got too high. I've been to Rock Mountain National Park. I can tell you what 12000 feet feels like. You get short of breath
very easily. And that was after having been up in the mountains for a few days. Someone who flew into Denver in the morning from someplace like New York and then drove directly up Trail Ridge Road to the top would likely collapse from lack of oxygen.
Finally, you have to consider the weather. The Eisenhower Tunnel isn't even quite above the treeline. Something that high in the Alps would be above the snowline, perpetually covered in ice and snowdrifts year round.
Quote from: voyager on January 29, 2009, 04:47:14 AM
Wonder what they are in Kansas? :-P
The highest point in Kansas is Mount Sunflower, is a couple dozen miles south of I-70 at Kanorado.
Would I-75 Alligator Alley constitute a low point?
The lowest interstate in Washington is almost certainly I-5 where it gets down towards Kelso- that's basically sea level right there.
The highest Interstate point in Wyoming and along I-80 is at Elevation 8640 by the WYO 210/Happy Jack Road interchange between Laramie and Cheyenne
I would guess in Minnesota the highest is I-35 coming into Duluth. The Sawtooth "Mountains" are the highest points of land in Minnesota and run along the North Shore, and I-35 crosses over one of them, Thompson Hill, on the way into Duluth.
Lowest: Also I-35 in Duluth maybe!!...Lake Superior's shoreline is the lowest point in Minnesota. I-35 comes within a couple hundred feet of the lake on the way to its terminus. Either that or I would say I-90 or I-94 in the western part of the state where the plains start.
What about Florida? :rolleyes:
Wouldn't be surprised if I-10's lowest point nationally was this location:
http://www.southeastroads.com/louisiana001/i-010_wb_exit_231b_03.jpg (http://www.southeastroads.com/louisiana001/i-010_wb_exit_231b_03.jpg)
The Railroad Underpass of Doom - Likely the lowest point in a city which itself is about 50% below sea level.
So low in elevation and so flood prone, the S&WB built a massive pumping station especially to drain the location (the square tan structure visible in the background).
Highest in WI has to be near Baldwin (near Eau Clare) on I-94
Lowest - I-43 in Green Bay
Quote from: Duke87 on January 29, 2009, 12:36:25 PM
... The Rockies are quite on the interior of the continent, whereas the Alps are, in general, much closer to the sea. This makes a climb equally high into the Alps much steeper, which would make altitude sickness a problem if the roads got too high. I've been to Rock Mountain National Park. I can tell you what 12000 feet feels like. You get short of breath very easily. And that was after having been up in the mountains for a few days. Someone who flew into Denver in the morning from someplace like New York and then drove directly up Trail Ridge Road to the top would likely collapse from lack of oxygen.
This was me. i flew to Denver from Detroit. As soon as I was in the rental, I was on my way to Mount Evans, elevation 14,280 feet, a difference of 13,780 feet in just over four hours. The air was so thin it was a five-minute walk from the driver's seat to the trunk.
Quote from: Duke87 on January 23, 2009, 08:31:49 PM
Quote from: Freewayjim on January 23, 2009, 04:38:10 PM
I-80 in PA is higher than I-93 in Northern New Hampshire or I-91 in Northern Vermont?
Poking around Google Earth indicates:
- I-87 getting upt to 1300 feet or so at a couple spots in the Adirondacks, but that's it.
- I-89 peaking at about 1700 feet south of Northfield, VT
- I-91 peaking at about 1900 feet north of Sheffield, VT
- I-93 peaking just shy of 2000 feet in Franconia Notch
- NY-17/I-86 peaking just above 2100 feet west of Karrdale
So that neck of the woods doesn't beat I-80.
However, I-64 gets up to about 2450 feet at the VA/WV line, so we can prove by counterexample that I-80 there is not the highest point on any interstate east of the Mississippi.
As to whether that one on I-64 is the highest... I don't know. I'm not running my mouse pointer along every interstate in the Appalcacians.
I-64 gets up to near 2800' at the top of Sandstone east of Beckley, WV. I believe I-77 at Flat Top south of Beckley is around 3200'.
Highest one in Texas is probably I-10 east of El Paso through the mountains in the Van Horn area. Although I-40 in the Panhandle is above 4,000 feet as well at the New Mexico border. No mountains, just high, flat plains.
Lowest is either I-45 at Galveston or I-37 at Corpus Christi (basically sea level). I-2 doesn't quite make it all the way to the Gulf.
Virginia:
Highest: 64 at the Va/Wv border.
Lowest: One of the tunnels in Hampton Roads, most likely.
Quote from: Urban Prairie Schooner on February 01, 2009, 04:29:15 PM
Wouldn't be surprised if I-10's lowest point nationally was this location:
http://www.southeastroads.com/louisiana001/i-010_wb_exit_231b_03.jpg (http://www.southeastroads.com/louisiana001/i-010_wb_exit_231b_03.jpg)
The Railroad Underpass of Doom - Likely the lowest point in a city which itself is about 50% below sea level.
So low in elevation and so flood prone, the S&WB built a massive pumping station especially to drain the location (the square tan structure visible in the background).
And I'd wager that the highest point would be on I-20 in Bienville parish somewhere. It's the hilliest section and not far from Mt. Driskill
I know that I-95's lowest point is probably the Fort McHenry Tunnel in Baltimore, but trying to find its highest point is hard being most of the road is the low lying coastal ranges it entire route.
Perhaps, it would most likely be in Maine as I am assuming that Appalachians due cross the path of I-95 there somewhere north of Augusta or maybe Bangor. I have not been up there ever, so I cannot have seen how the road is there.
I-4 is probably the most toughest as the whole elevation of Florida is less than 1000 feet. You do not see much action on I-4 as far as hill climbing its entire run, and the land seems relativity flat . I could not tell either point with this interstate.
I-75 on the other hand you could guess that its southern terminus is the lowest, being close to Miami, and the mountain range just south of the KY-TN state line is the highest. However, just because you climb to get someplace does not mean you are at the highest either as we have many high points even on flat ground. Look at Dodge City, KS being higher in elevation that many peaks on the Appalachians. Dodge too is on flat ground, but the land of the continent has a slow upward slope west of the Mississippi River into the Rockies that causes that. Therefore the climb to get to Dodge is not at all noticeable, so maybe a GA may have higher places along the route that does not require drastic climbs.
Another way of looking at this question is the longest continuous stretch of interstate above whatever threshold you consider to be "high altitude". If you pick 3000 feet, for east-west routes it's likely I-40, which is above that elevation continuously from west of Kingman AZ to east of Amarillo TX. I would guess that distance to be in the neighborhood of 700 miles. I-70 might come close to that, since you cross the 3000 foot contour somewhere east of Oakley KS. And, it just occurred to me that all of I-25 is likely above that elevation, so that would make it the longest overall route, at about 1050 miles. This isn't as significant a measurement, since I-25 basically follows the Rockies, so it is by virtue of its location at a higher elevation.
Quote from: Thing 342 on December 09, 2013, 06:30:42 AM
Virginia:
Highest: 64 at the Va/Wv border.
Lowest: One of the tunnels in Hampton Roads, most likely.
I-77 reaches about 3000 ft just south of the Walker Tunnel...
Mapmikey
I don't have Google Earth so I can't be very precise, but for Indiana the lowest would be near the 5.2 mile mark of I-69/164 in Evansville.
Highest would be near the 152 mile mark of I-70 near Richmond.
Quote from: SSOWorld on January 29, 2009, 09:13:38 AM
Highest point in the Nation? I-70 (Eisenhower Tunnel in Colorado)
Lowest point in the Nation? My guess is I-8 in the Imperial Valley, California.
Yeah this is probably it
Damn Nimbyans for canceling I-420.
Quote from: TheHighwayMan394 on January 31, 2009, 07:56:33 PM
I would guess in Minnesota the highest is I-35 coming into Duluth. The Sawtooth "Mountains" are the highest points of land in Minnesota and run along the North Shore, and I-35 crosses over one of them, Thompson Hill, on the way into Duluth.
Lowest: Also I-35 in Duluth maybe!!...Lake Superior's shoreline is the lowest point in Minnesota. I-35 comes within a couple hundred feet of the lake on the way to its terminus. Either that or I would say I-90 or I-94 in the western part of the state where the plains start.
Actually, you've got the highest point backwards. It doesn't look like I-35 around Duluth gets higher than about 1300'. Exit 249, Boundary Ave, is 1191'. Impressive when that's 700 feet above the lake, but I-94 reaches 1416' at the rest area near Alexandria. I-90 is actually above 1400' at the South Dakota state line and seems to top out at just over 1700' west of Worthington.
This seems to be true of most states: the flat points far away from the coast (or biggest river, or whatever) are higher than the "mountains" near it. Not always, since Eagle Mountain is right by Lake Superior, but in general it makes highpointing nice and boring.
Quote from: SSOWorld on February 02, 2009, 02:55:16 PM
Highest in WI has to be near Baldwin (near Eau Clare) on I-94
Lowest - I-43 in Green Bay
If I-39 ever found its way further north, it would eclipse that by a couple hundred feet around Brokaw.
Specifically, the lowest point on I-43 would be right around its northern terminus at US 41 as it crosses the Duck Creek Estuary.
The addition of I-41 will not result in a 'tie' since I-41 will end at I-43 and crosses over it at that point.
The coming reconstruction of this future double I-terminus will also not change this.
Not sure about New Jersey. If I was to guess the highest would probably be somewhere in the western part along I-78 or I-80. The lowest would probably also be I-78 in the Holland Tunnel.
Quote from: roadman65 on December 09, 2013, 10:27:49 AM
I know that I-95's lowest point is probably the Fort McHenry Tunnel in Baltimore, but trying to find its highest point is hard being most of the road is the low lying coastal ranges it entire route.
Perhaps, it would most likely be in Maine as I am assuming that Appalachians due cross the path of I-95 there somewhere north of Augusta or maybe Bangor. I have not been up there ever, so I cannot have seen how the road is there.
I-95 between Bangor and Houlton is remarkably flat. It is possible to see Mount Katahdin (https://en.wikipedia.org/wiki/Mount_Katahdin) to the west of the freeway in Baxter State Park, but the mountain "stands alone" around relatively flat (never close to 1,000 feet above sea level) and mostly forested lands.
Quote from: ap70621 on December 10, 2013, 12:43:53 AM
Not sure about New Jersey. If I was to guess the highest would probably be somewhere in the western part along I-78 or I-80. The lowest would probably also be I-78 in the Holland Tunnel.
Another highest possibility would be I-287 in the north. I tried checking, but:
* Google Maps is stuck in Preview mode, which doesn't show Terrain lines dark enough or at the necessary zoom level
* Acme maps re-centers the page every time I try to zoom in on the Topo
* I am too impatient to keep trying
Quote from: corco on January 31, 2009, 03:45:49 PM
The lowest interstate in Washington is almost certainly I-5 where it gets down towards Kelso- that's basically sea level right there.
Nosing at Google Earth shows that I-5 only gets to the single digits in elevation closer to Woodland than Kelso. But feel free to question its accuracy; it gives the elevation of the I-90 floating bridge at ~1 foot, when any other source I can find lists Lake Washington's elevation at around 16 feet.
Quote from: Steve on December 10, 2013, 08:34:18 PM
Quote from: ap70621 on December 10, 2013, 12:43:53 AM
Not sure about New Jersey. If I was to guess the highest would probably be somewhere in the western part along I-78 or I-80. The lowest would probably also be I-78 in the Holland Tunnel.
Another highest possibility would be I-287 in the north. I tried checking, but:
* Google Maps is stuck in Preview mode, which doesn't show Terrain lines dark enough or at the necessary zoom level
Some of the contour lines seem to be missing in Google, but that section of I-287 south of the New York/New Jersey border appears to be between 700' and 800' in elevation.
Seems like in Massachusetts, the highest is the Mass Pike.
Beaten by MA 2, however, with 2000 feet.
Are there any other major routes in Massachusetts (maybe US 7) that are higher than MA 2?
Quote from: SSOWorld on February 02, 2009, 02:55:16 PM
Highest in WI has to be near Baldwin (near Eau Clare) on I-94
Lowest - I-43 in Green Bay
Actually, I'm thinking that the highest in WI would be somewhere on I-39 in the Wausau area (near the CWA airport?), while the lowest would be I-90 at the Mississippi River in La Crosse.
Remember that the lowest point in Wisconsin is at the Illinois state line where it meets the Mississippi River shoreline.
Mike
Which in turn means the lowest point in WI is close to the WI/IL/IA tripoint near Dubuque IA.
I cannot believe the highest point in the interstate system, the Eisenhower tunnel on I-70 in CO, is just 10 feet shorter than the highest peak in my region :wow:. But wait till China builds a couple of expressways through the Tibet, they will go up of 17,000 feet above sea level!!!
Quote from: CNGL-Leudimin on December 14, 2013, 07:59:46 AMBut wait till China builds a couple of expressways through the Tibet, they will go up of 17,000 feet above sea level!!!
I doubt China will build more than one, and they chose rail rather than road when the 'bring the wild west closer to the east' plan took place. Urumqi got roads, not rail, so a Tibetan expressway isn't too likely.
Quote from: mgk920 on December 14, 2013, 01:00:34 AM
Actually, I'm thinking that the highest in WI would be somewhere on I-39 in the Wausau area (near the CWA airport?), while the lowest would be I-90 at the Mississippi River in La Crosse.
For highest point, we may have a tie. Both I-94 by exit 28 (WI 128) and I-39 by the airport in Mosinee touch a 1280' contour. Someone needs to verify in the field!
Quote from: mgk920 on December 14, 2013, 01:00:34 AMRemember that the lowest point in Wisconsin is at the Illinois state line where it meets the Mississippi River shoreline.
Not true.
Normal pool elevation of the Mississippi at Dubuque below lock and dam number 11 is 592 feet above MSL. The surface of Lake Michigan is 577 feet above MSL.
Quote from: triplemultiplex on December 14, 2013, 06:55:13 PM
Quote from: mgk920 on December 14, 2013, 01:00:34 AM
Actually, I'm thinking that the highest in WI would be somewhere on I-39 in the Wausau area (near the CWA airport?), while the lowest would be I-90 at the Mississippi River in La Crosse.
For highest point, we may have a tie. Both I-94 by exit 28 (WI 128) and I-39 by the airport in Mosinee touch a 1280' contour. Someone needs to verify in the field!
Quote from: mgk920 on December 14, 2013, 01:00:34 AMRemember that the lowest point in Wisconsin is at the Illinois state line where it meets the Mississippi River shoreline.
Not true.
Normal pool elevation of the Mississippi at Dubuque below lock and dam number 11 is 592 feet above MSL. The surface of Lake Michigan is 577 feet above MSL.
If that is indeed the case, then the lowest would be on I-43 for a distance eastward from its interchange with US(I)-41 (Howard Interchange). I-794 is elevated over its entire length, I-43 and 94 in Milwaukee County are all above the bluffs while that part of I-43 in the Green Bay area runs low through a swampy shoreline area. East of the Fox River bridge, the lowest parts of I-43 are on higher fill.
Maybe I was thinking of Illinois here - the lowest point in IL is at the Mississippi-Ohio River confluence in Cairo. That should make I-57 in that area the lowest I-route in Illinois.
Mike
Maine:
Low: I-295 at the gores at the north side of Exit 7.
High: I-95 at roughly Mile 289.
Quote from: Kacie Jane on December 10, 2013, 09:12:29 PM
Quote from: corco on January 31, 2009, 03:45:49 PM
The lowest interstate in Washington is almost certainly I-5 where it gets down towards Kelso- that's basically sea level right there.
Nosing at Google Earth shows that I-5 only gets to the single digits in elevation closer to Woodland than Kelso. But feel free to question its accuracy; it gives the elevation of the I-90 floating bridge at ~1 foot, when any other source I can find lists Lake Washington's elevation at around 16 feet.
I would guess that the lowest elevation on I-5 in Washington is where it crosses the Snohomish River Delta between Everett & Marysville. That area is wetlands that were reclaimed by levees and the elevation is as low as 2 feet in places. I-5 would have to dip below the level of the Columbia River to get to single digits in elevation up river from Longview.
I-5's highest point in Washington is where it crosses Chuckanut mountain just south of Bellingham.
I've done some digging around, and I can say with some confidence that the lowest point on the Interstate Highway System in Illinois is 298 feet, on I-57, where it crosses the Mississippi River near Cairo.
The highest point is 976 feet, on I-90, just east of its junction with US-20 near Hampshire.
Coming in second is 939 feet, on I-88, just east of its junction with I-39 near Rochelle.
That's a total variation of less than 700 feet.
Quote from: mgk920 on December 14, 2013, 10:29:16 PM
Quote from: triplemultiplex on December 14, 2013, 06:55:13 PM
Quote from: mgk920 on December 14, 2013, 01:00:34 AM
Actually, I'm thinking that the highest in WI would be somewhere on I-39 in the Wausau area (near the CWA airport?), while the lowest would be I-90 at the Mississippi River in La Crosse.
For highest point, we may have a tie. Both I-94 by exit 28 (WI 128) and I-39 by the airport in Mosinee touch a 1280' contour. Someone needs to verify in the field!
Quote from: mgk920 on December 14, 2013, 01:00:34 AMRemember that the lowest point in Wisconsin is at the Illinois state line where it meets the Mississippi River shoreline.
Not true.
Normal pool elevation of the Mississippi at Dubuque below lock and dam number 11 is 592 feet above MSL. The surface of Lake Michigan is 577 feet above MSL.
If that is indeed the case, then the lowest would be on I-43 for a distance eastward from its interchange with US(I)-41 (Howard Interchange). I-794 is elevated over its entire length, I-43 and 94 in Milwaukee County are all above the bluffs while that part of I-43 in the Green Bay area runs low through a swampy shoreline area. East of the Fox River bridge, the lowest parts of I-43 are on higher fill.
Maybe I was thinking of Illinois here - the lowest point in IL is at the Mississippi-Ohio River confluence in Cairo. That should make I-57 in that area the lowest I-route in Illinois.
Mike
One more thought here, what is the elevation of US(I)-41 at the top of that hill between WI 60 and WI 144 in Slinger? That is the highest point on US 41 north of Tennessee.
Mike
Quote from: un1 on January 21, 2009, 08:25:15 PM
The highest point on the Interstate Highway System is at the Eisenhower Tunnel on Interstate 70 in the Rocky Mountains of Colorado, at the Continental Divide (elev. 11,158 ft/3,401 m).
The lowest point on land is on Interstate 8 at the New River near Seeley, California (elev. -52 ft/−16 m).
The lowest point under water is on Interstate 95 in the Fort McHenry Tunnel under the Inner Harbor in Baltimore, Maryland (elev. -107 ft/−33 m).
Source: Wikipedia
In Québec, quite a few autoroutes lick the 400 metres (1,300 feet) contour line (A-10 near Orford mountain, A-15 south of Sainte-Agathe-des-Monts, A-73 at its northern end near Jacques-Cartier National Park entrance.
If the A-73 is ever applied to R-175 through Laurentides Park, that would break any mark, setting it at 940 metres (3,100 feet) near Montmorency forest. Upon completion, A-85 will reach 430 metres (1,400 feet) near Saint-Honoré.
The lowest autoroute is probably A-20 in Rivière-du-Loup, at sea level, through the intertidal zone.
(Not interstates, I know)
I-26 near the TN/NC border goes through Sam's Gap at 3,770 ft. Wouldn't this be the highest interstate point east of the Mississippi River?
-Ed S
Quote from: CtrlAltDel on April 09, 2014, 03:49:01 PM
I've done some digging around, and I can say with some confidence that the lowest point on the Interstate Highway System in Illinois is 298 feet, on I-57, where it crosses the Mississippi River near Cairo.
The highest point is 976 feet, on I-90, just east of its junction with US-20 near Hampshire.
Coming in second is 939 feet, on I-88, just east of its junction with I-39 near Rochelle.
That's a total variation of less than 700 feet.
We are flat-landers in the Prairie State, what can I say?
Oh, and I've driven all 3 of those points!
Quote from: ilpt4u on October 17, 2018, 09:25:24 PM
Quote from: CtrlAltDel on April 09, 2014, 03:49:01 PM
I've done some digging around, and I can say with some confidence that the lowest point on the Interstate Highway System in Illinois is 298 feet, on I-57, where it crosses the Mississippi River near Cairo.
The highest point is 976 feet, on I-90, just east of its junction with US-20 near Hampshire.
Coming in second is 939 feet, on I-88, just east of its junction with I-39 near Rochelle.
That's a total variation of less than 700 feet.
We are flat-landers in the Prairie State, what can I say?
Oh, and I've driven all 3 of those points!
Second flattest in the US!
Quote from: Wadsteckel on October 17, 2018, 09:02:49 PM
I-26 near the TN/NC border goes through Sam's Gap at 3,770 ft. Wouldn't this be the highest interstate point east of the Mississippi River?
-Ed S
Thanks for reviving this thread, It's a good read.
Since this thread got bumped, I'll do Utah.
The highest interstate in Utah is I-70 over Emigrant Pass (between Salina and Fremont Junction), which is also its crossing of the Great Basin Divide. The elevation of this pass varies depending on who you ask, but Google Earth puts it at 7849 feet.
The lowest point is on I-15 in St George, at the bridge over the Virgin River in Washington County near St. George. Google Earth gives an elevation value of approximately 2550 feet.
Come to think of it, I-15 is the only interstate in Utah that even drops below 4000 feet. I-70 comes closest, getting to about 4050 feet at the Green River bridge. I-80, 84, and 215 all have low points in the vicinity of 4220 feet, near the Great Salt Lake which sits at 4200 feet on average.
Quote from: CtrlAltDel on October 18, 2018, 03:20:43 PM
Quote from: inkyatari on October 17, 2018, 10:16:32 PM
Second flattest in the US!
How so?
This article explains it...
https://news.nationalgeographic.com/news/2014/03/140314-flattest-states-geography-topography-science/
http://www.disruptivegeo.com/blog/wp-content/uploads/2014/08/FlatMap_GeographicalReview_DobsonCampbell_2013Nov.pdf
MN:
Highest: I-90 west of Worthington (1,702)
Lowest: I-35 along the Duluth lakeshore (618)
In Ohio, the highest point appears to be around MP 167 on I-71 a few miles south of Mansfield, at just under 1400 ft. The lowest, both at about 490 ft, are where I-275 crosses into Indiana and the Ft Washington Way Trench of I-71 in Cincinnati.
I don't know if Ohio has signed it on other routes, but on I-75 there are signs where you cross from the Ohio River watershed to the Lake Erie Watershed, around MP 106.
Quote from: inkyatari on October 18, 2018, 03:31:11 PM
Quote from: CtrlAltDel on October 18, 2018, 03:20:43 PM
Quote from: inkyatari on October 17, 2018, 10:16:32 PM
Second flattest in the US!
How so?
This article explains it...
https://news.nationalgeographic.com/news/2014/03/140314-flattest-states-geography-topography-science/
http://www.disruptivegeo.com/blog/wp-content/uploads/2014/08/FlatMap_GeographicalReview_DobsonCampbell_2013Nov.pdf
That was an interesting link from NatGeo, but it seemed like the article ended abruptly. The .pdf is better. I'm not 100% on board with how the authors define flatness. I think that I'd weigh Percentage of State Area in Flattest Category very highly and move LA up to #2 and WY down to the bottom 5, but I'm not a geographer.
Ok, I'll try CT for interstates
Highest point: I-84 in Middlebury between Exit 16-17 is about 750 feet above sea level. Just beats out I-84 between Exit 68 and 69 in Tolland (about 720 feet)
Lowest point: I-95 in New Haven right along Long Wharf. Can't be much more than 5 feet above sea level.
And RI:
High point: I-95 in West Greenwich just south of the RI 102 interchange is about 500 feet above sea level
Low point: I-95 in downtown Providence is about 20-30 feet above sea level. If it were not on a high bridge, I-195 at the Providence River would be the lowest.
I wonder which potential interstate frustrated engineers the most
Quote from: texaskdog on October 19, 2018, 01:23:03 PM
I wonder which potential interstate frustrated engineers the most
I can't imagine anything besides I-70. The tunnels, Glenwood, high mountain passes, just general mountain construction in general, the avalanches that affect the route every winter.
Quote from: jp the roadgeek on October 19, 2018, 01:36:06 AM
Ok, I'll try CT for interstates
Highest point: I-84 in Middlebury between Exit 16-17 is about 750 feet above sea level. Just beats out I-84 between Exit 68 and 69 in Tolland (about 720 feet)
Lowest point: I-95 in New Haven right along Long Wharf. Can't be much more than 5 feet above sea level.
And RI:
High point: I-95 in West Greenwich just south of the RI 102 interchange is about 500 feet above sea level
Low point: I-95 in downtown Providence is about 20-30 feet above sea level. If it were not on a high bridge, I-195 at the Providence River would be the lowest.
DIGRESSION:
That's part of my commute. There are two weigh stations/rest areas nearby. The southbound one has been taken over by a construction company as a staging area. At first, I thought that it was for the nearby toll gantry, but that project ended months ago. Is there sitill some nearby construction? This is a question that's been lingering in the back of my head for some time. Your post reminded me to finally ask that question.
Idaho
Lowest: I-90 at Stateline (WA border) - 2057 ft (Gonna be honest, I was expecting I-84 at Ontario, OR border to be the lowest; it's about 80 ft higher)
Highest: I-15 at Monida (MT border) - 6870 ft
Interesting thing is that there are a lot (well okay, a lot of it is remote canyons) of areas in Idaho with lower elevation than 2057 ft, but interstates go nowhere near them. The lowest (both the lowest highway, and the lowest point in the entire state, period) being Lewiston, roughly 720 ft on US-12 crossing into WA (sources say 710 ft at river level).
Looks like the highest point on a state highway in ID is Galena Summit on ID-87 between Ketchum and Stanley, 8,701 ft. Though I could be missing something there.
I have been to all 4 of those points, so yay.
Quote from: Urban Prairie Schooner on February 01, 2009, 04:29:15 PM
Wouldn't be surprised if I-10's lowest point nationally was this location:
http://www.southeastroads.com/louisiana001/i-010_wb_exit_231b_03.jpg (http://www.southeastroads.com/louisiana001/i-010_wb_exit_231b_03.jpg)
The Railroad Underpass of Doom - Likely the lowest point in a city which itself is about 50% below sea level.
So low in elevation and so flood prone, the S&WB built a massive pumping station especially to drain the location (the square tan structure visible in the background).
I-10 east of Indio, CA, is about 40 ft BSL. I believe New Orleans only gets down to 10-12 ft BSL.
Many people don't realize it wouldn't take much to have a salt water port in the Coachella Valley. The saddle between the Gulf of California/ Sea of Cortez and the Salton Sea is only about 40 ft ASL. Breach that and the entire Imperial Valley and the east end of the Coachella Valley are underwater.
I didn't notice Michigan in this thread yet.
Probably both the highest and lowest points are both on I-75. Certainly the lowest is I-75 along Lake Erie. I'd guess the highest is somewhere up near Gaylord.
Quote from: skluth on October 19, 2018, 06:08:10 PM
Many people don't realize it wouldn't take much to have a salt water port in the Coachella Valley. The saddle between the Gulf of California/ Sea of Cortez and the Salton Sea is only about 40 ft ASL. Breach that and the entire Imperial Valley and the east end of the Coachella Valley are underwater.
Related: https://what-if.xkcd.com/152/
Anyone know Indiana's?
Quote from: Interstate 69 Fan on October 19, 2018, 08:47:07 PM
Anyone know Indiana's?
I would hazard guesses that both are in the southern part of the state, with I-164 in Evansville being the lowest. Might a spot on I-69 southwest of Bloomington be the highest?
Mike
Quote from: inkyatari on October 18, 2018, 03:31:11 PM
Quote from: CtrlAltDel on October 18, 2018, 03:20:43 PM
Quote from: inkyatari on October 17, 2018, 10:16:32 PM
Second flattest in the US!
How so?
This article explains it...
https://news.nationalgeographic.com/news/2014/03/140314-flattest-states-geography-topography-science/
http://www.disruptivegeo.com/blog/wp-content/uploads/2014/08/FlatMap_GeographicalReview_DobsonCampbell_2013Nov.pdf
It seems that flatness here is defined as "antisteepness," in that it's not the actual height differences that matter but how gently you get from one to the other. It's an interesting idea. Out of idle curiosity, I wonder how Olympus Mons, given the sheer size of its base, would fit in this schema.
Quote from: Interstate 69 Fan on October 19, 2018, 08:47:07 PM
Anyone know Indiana's?
As far as I can tell, the low point, at 370 feet, is on I-69 near its terminus with US-41 in Evansville. The high point, at 1,116 feet, is on I-70 at the Ohio border.
Quote from: GaryV on October 19, 2018, 07:15:12 PM
I didn't notice Michigan in this thread yet.
Probably both the highest and lowest points are both on I-75. Certainly the lowest is I-75 along Lake Erie. I'd guess the highest is somewhere up near Gaylord.
Without researching it, I would have to agree with you on both counts.
Maine:
Low point is on I-295, however many feet above sea level they filled in Back Cove to build the roadbed. Between exits 7 & 8. < 20 feet.
High Point is 740 feet, on I-95 just north of where it enters the town of Smyrna in Aroostook County.