Best Engineering for an Interstate Highway

[Fcexpress80]

Nominations are open.

Considerations for environment, preserving scenery, as well as novel thinking into design.

Many have mentioned 1-70 from the Ike Tunnel to the Utah border as a wonder in engineering.  This highway is not unique as there are many similar designs, albeit not as long or complex.  Consider these "canyon" interstates that I have personally travelled on:

I-15 north of Helena, MT.  I remember the construction of this portion and was impressed with how it all came together.

I-84, the Columbia Gorge.  This freeway has evolved over the decades.  The railroads owned much of the land right next to the Columbia River forcing roadway builders up above the river along the cliffs.  Many sections of the original two lane Gorge Highway built along the cliffs are now closed to auto traffic and make outstanding bike and hiking trails.

I-90, the western approach to Snoqualmie Pass in WA State.  The eastbound lanes occupy the previous 2x2 US-10 along the south side of the valley.  The newer westbound lanes utilize a mile long viaduct over the avalanche prone north side of the valley.

I-90, Wallace, ID.  The town occupied the valley so the freeway was built on the hill above the town with viaducts that almost "fly over" the town.  Not to mention the portion in the same area that also was built to bypass Lake Couer 'd Alene.  The old highway along the lake is now a boulevard with little traffic and a favorite of strollers, bikers, and skaters.

I-93 through Franconia Notch, NH.  One of the few places an Interstate Freeway is reduced to "super 2" status (this may not be the case now as it was when I drove it).  Got to see the "Old Man" before it slid off the mountainside a few years back.

There are probably many other places where geography and engineering meet to create scenic and spectacular roadways.  I open it up to the forum....

[SSOWorld]

I-70 through Glenwood Canyon.  some piece of work.  having to tunnel at times, and build on the side of a cliff (having WB lanes higher than EB to reduce the space used by the road.  beautiful scenery for an interstate - painted the same color as the cliff to have it blend in somewhat.  Worked at a Dam on the Colorado for two weeks installing generator equipment (as a contractor) - it was right under the interstate.

[Bryant5493]

I think GDOT did a good job with the Wayne Shackelford Interchange (I-85/Veterans Parkway @ S.R. 316/University Parkway).

http://www.youtube.com/watch?v=gzZ2GVfXvYA

Also, I like the Buford Highway (U.S. 23/S.R. 13) and Pleasant Hill Road interchange.

http://www.youtube.com/watch?v=dHa6tYIgWBY


Be well,

Bryant

[Alex]

In Philadelphia: Interstate 676 (Vine Street Expressway) and Interstate 95 (Delaware Expressway) by Penn's Landing, both built below grade with cut and cover tunnels supporting urban parks.

[UptownRoadGeek]

hmm. I'll say the I-10/U.S. 61/S. Carrollton interchange in NOLA.

It was built over an already existing complex interchange and railroad tracks, then incorporated into the interchange and one of the streets below without removing or changing any of the existing structures.

Not sure if that counts, but I'm fascinated with the thing

[Fcexpress80]

Cut and cover seems to be environmentally in nowadays, albeit more expensive.  I-90 through Seattle and Mercer Island is one example of an urban freeway with parks over it on "lids."  Travel 3,000 miles east on I-90 and you find the Mass Turnpike and its extension to Logan Airport in Boston with similar cut and cover sections and tunnels.  

Even ADOT in Anchorage, AK is proposing a "cut and cover" freeway connecting existing freeway portions between the Seward Highway (the future "I-A3") and the Glenn Highway ("I-A1").  

Google Earth reveals many freeways worldwide that are cut and cover in urban areas including a fantastically engineered M-1 Expressway in Melbourne, Australia:
(Google Earth: 37* 49' 35.3" S and 144* 57' 58.1" E)

[bugo]

The "middle" (Fayetteville to Alma) segment of I-540 is quite the engineering marvel.  And extremely scenic to boot.

[Scott5114]

I am always impressed with Kansas freeways. Not that they're anything special in terms of engineering–Kansas probably has some of the easiest terrain a roadbuilder could wish for–but they are for the most part designed with care and expertise. The curves are banked just right, the pavement smooth, the merging space adequate.

[74/171FAN]

I-95 at the Springfield Interchange(I-395/I-495) and soon to be I-95/I-495 from VA 241/Telegraph Rd over the fairly new Woodrow Wilson Bridge to MD 210

[bugo]

I am always impressed with Kansas freeways. Not that they're anything special in terms of engineering–Kansas probably has some of the easiest terrain a roadbuilder could wish for–but they are for the most part designed with care and expertise. The curves are banked just right, the pavement smooth, the merging space adequate.

Yes, Kansas does have nice smooth highways for the most part.  Which is even more impressive considering the wintry weather they get every year.  It's quite a contrast crossing into Kansas from Missouri or Oklahoma.

[agentsteel53]

US-95 at White Bird Grade in Idaho.

the old alignment is a classic 1920s serpentine up the hill, but in 1975 they replaced it with a three to four lane climb, with a bridge crossing the valley.



Terrible photo of the new bridge, as seen from the old alignment.

[njroadhorse]

I-15 through the Virgin River Gorge in Arizona.

[hm insulators]

I-5 from the top of Tejon Pass down to the San Joaquin Valley.