Bridges that had major alterations after they were put into service.

[Jardine]

The toll booths on the original Hiway 30 bridge over the Missouri River at Blair Nebraska were midspan and cantilevered out from the bridge structure.  Weren't too many people that liked stopping in the middle of the bridge with the metal grate decking and were happy to see them removed.

The existing 2 way bridge over the Missouri connecting Florence/Omaha to Crescent, Iowa was incorporated into I-680 as the eastbound structure.  It was redecked to make the lanes as wide as possible within the existing steel frame.  I think the railings were redone in a thinner concrete design than the existing metal ones.  The bridge is still narrow for an Interstate bridge.

I don't know if the south bound I-29 bridge over the Big Sioux River just north of Sioux City was modified or replaced after the northbound structure collapsed just a few months after opening.  I guess if it was ripped out and totally rebuilt after just a few months service that would be an extreme case for the topic.

[Pete from Boston]

The Maurice J. Tobin Mystic River Bridge had its west end, a former "Y" setup merging its upper and lower decks with those of I-93, rebuilt as a descending viaduct into a tunnel and connecting up to surface streets and an enormous helix on the other side of 93.

It also has had the toll booths mounted up on the bridge removed.

[SteveG1988]

Clay's Ferry bridge in KY, twin span converted into one massive connected span.

http://bridgehunter.com/ky/fayette/clays-ferry/

Edit:

Did some research, i am 95% in agreement that they are brand new spans on the original piers with a central pier added in the 90s. Looking at old photos, the trusses had oval holes in the beams, the bridge lacks any oval holes in 2015.

[Big John]

Clay's Ferry bridge in KY, twin span converted into one massive connected span.

http://bridgehunter.com/ky/fayette/clays-ferry/

Edit:

Did some research, i am 95% in agreement that they are brand new spans on the original piers with a central pier added in the 90s. Looking at old photos, the trusses had oval holes in the beams, the bridge lacks any oval holes in 2015.

And reading the report, I don't like erroneous information put in it.  I am looking at the deck width listed at 60'.  With 6 full lanes and shoulders that look like standard width, the real width is a little over 100'.  And the incorrect width imputed is giving it an artificially low sufficiency rating and moreso, gives it a bad label of "functionally obsolete".

[SteveG1988]

Clay's Ferry bridge in KY, twin span converted into one massive connected span.

http://bridgehunter.com/ky/fayette/clays-ferry/

Edit:

Did some research, i am 95% in agreement that they are brand new spans on the original piers with a central pier added in the 90s. Looking at old photos, the trusses had oval holes in the beams, the bridge lacks any oval holes in 2015.

And reading the report, I don't like erroneous information put in it.  I am looking at the deck width listed at 60'.  With 6 full lanes and shoulders that look like standard width, the real width is a little over 100'.  And the incorrect width imputed is giving it an artificially low sufficiency rating and moreso, gives it a bad label of "functionally obsolete".

It's like nobody is quite sure what the heck it is. But it is a neat conversion anyway, as the new spans are actually variants on what was there before, probably for weight purposes.

[Buffaboy]

This was the "Father Baker Bridge" in Lackawanna, NY.



It's a mythical bridge, and has since been replaced by this:

[empirestate]

This was the "Father Baker Bridge" in Lackawanna, NY.



It's a mythical bridge, and has since been replaced by this:

I'm pretty sure that's just a whole new bridge.

[triplemultiplex]

Check out this Frankenstein bridge over the Wailua River on the island of Kauai.





It's an old narrow-gauge railroad bridge with a two lane road bridge piggy backed on top of it.  It carries the NB lanes of SR 56.
You might also notice an old abutment for a narrow road bridge between the two existing bridges.  Seems to be the bridge that the piggybacked one replaced.

[wriddle082]

The Silliman Evans Bridge in Nashville, TN.  Originally built in the early 60's to carry I-65 over the Cumberland River (near the current Nissan Stadium), then later I-24 was added after its NW extension finally fully opened around 1980, now it carries only I-24, as I-65 was rerouted around the west side of the Nashville loop along I-40 and former I-265 in 2000.

I don't have a lot of concrete info to back this up, but I believe the original layout was (2) 3-lane spans with little to no shoulders.  Sometime in the mid-late 70's (based on the bridge parapets before they were upgraded within the past 10 years), the spans were widened to four lanes each with full shoulders, which also coincided with adding additional lanes to the I-40 interchange immediately east (literally south) of the bridge.  The spans were widened by welding/attaching wing spans to the outside girders.  There are four continuous lanes on the eastbound span, but it's worth noting that the westbound span has the leftmost lane drop somewhere in the middle while simultaneously creating an exit-only lane on the right for the Shelby Ave/Gateway Blvd exit.

This GSV link takes you to Davidson St underneath the bridge:
https://www.google.com/maps/@36.1610329,-86.7603819,3a,37.5y,181.02h,90.11t/data=!3m6!1e1!3m4!1svfsM4Xmx4zo4U2ARQzxkFA!2e0!7i13312!8i6656!6m1!1e1

On the portions of the bridge that cross land, it simply has standard beams added to the sides with additions made to the piers.  It's hard to see if you zoom in, but the piers over the river itself appear to be narrower, which should be their original width.

Looks like Google hit up this area after a recent rehab, as everything appears freshly painted/texture-coated.

Another one in Nashville is the I-440 EB flyover ramp to I-24 WB, also connecting to I-40 EB and WB:
https://www.google.com/maps/place/Nashville,+TN/@36.126724,-86.7277886,3a,75y,300.57h,90.57t/data=!3m7!1e1!3m5!1sTmSA9keUsQto7P3N11330A!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DTmSA9keUsQto7P3N11330A%26output%3Dthumbnail%26cb_client%3Dsearch.TACTILE.gps%26thumb%3D2%26w%3D96%26h%3D64%26yaw%3D176.88503%26pitch%3D0!7i13312!8i6656!4m2!3m1!1s0x8864ec3213eb903d:0x7d3fb9d0a1e9daa0!6m1!1e1

Originally opened in 1986 as a single lane flyover, this one quickly caused serious afternoon rush hour backups throughout the late 80's and most of the 90's.  I believe by 1997 or 1998, it was finally widened to two lanes by adding a girder to the outside of each "tub" and widening the deck accordingly, which was not easy.

This "tub" bridge style (not sure what the correct term for this is) is in use at all (3) of I-440's interstate interchanges (the I-24 interchange is painted red, the I-65 symmetrical stack is  yellow, and the I-40 interchange is brown), plus the flyover on-ramp at I-40 Exit 216A coming from the BNA terminal has one of these bridges painted brown, and the I-40 EB ramp to I-640 WB in East Knoxville has one of these bridges painted blue.  Does anybody know the correct term for this style of bridge, and have examples from other states?

[jwolfer]

Check out this Frankenstein bridge over the Wailua River on the island of Kauai.





It's an old narrow-gauge railroad bridge with a two lane road bridge piggy backed on top of it.  It carries the NB lanes of SR 56.
You might also notice an old abutment for a narrow road bridge between the two existing bridges.  Seems to be the bridge that the piggybacked one replaced.

Sort of like the Bahia Honda bridge in the Florida keys.. The road was built on top of the trusses for the railroad bridge. I am having trouble attaching images in tapatalk app.. Look up images pretty cool

[Jardine]

Lower deck was added to the George Washington suspension bridge.

Some/most/all the bridges over the Cape Cod canal were raised.

Meridian Bridge had lift span mechanism removed, and upper level 2 way was made one way when lower level train tracks were removed and made into one way the other way for vehicles

I believe the original Aksarben Bridge was 2 lanes and was doubled to 4

Similarly, I think the original Sioux City to South Sioux City Bridge had additional lanes cantilevered out from the existing 2 lane bridge.  I went over it as a kid, it must have been a scary thing, a 4 lane bridge, but with the 2 lanes in each direction divided by the steel structure, and the 2 opposing inside lanes had no divider.  Probably a very unusual arrangement.

Don't know if this counts per the topic but the Decatur Nebraska Missouri River Bridge was originally built in a corn field, and then several years later had the river rerouted beneath it. (bridge was useless before the river was moved, took an act of Congress which is the why of the delay)

[davewiecking]

Does Key Bridge between Georgetown and Rosslyn count? Built as 4 lanes with sidewalks on each side; converted to 6 lanes with both sidewalks cantilevered.

[SteveG1988]

Does Key Bridge between Georgetown and Rosslyn count? Built as 4 lanes with sidewalks on each side; converted to 6 lanes with both sidewalks cantilevered.

Debatable, was there a massive structural change, or just the sidewalk change?

https://en.wikipedia.org/wiki/Old_Trails_Bridge

Topock bridge, converted to a pipeline bridge once I40 was completed.

[davewiecking]

Does Key Bridge between Georgetown and Rosslyn count? Built as 4 lanes with sidewalks on each side; converted to 6 lanes with both sidewalks cantilevered.

Debatable, was there a massive structural change, or just the sidewalk change?

The iconic (to use an overused word) supporting arches were unchanged. I believe half the roadbed was torn up, and then replaced with a unitary reinforced (larger) slab. Then ditto on the other half. So I guess the answer is "no"...

[triplemultiplex]

Sort of like the Bahia Honda bridge in the Florida keys.. The road was built on top of the trusses for the railroad bridge. I am having trouble attaching images in tapatalk app.. Look up images pretty cool

I thought of that too.  This Hawaii one is an exaggerated version of that conversion since the existing bridge was so narrow.  Two bicycles would have trouble passing each other on the old narrow gauge bridge.

[SteveG1988]

Chicago skyway had all of the approach piers replaced. I think they were steel before, and are concrete now.

[cappicard]

I'd say the Bay Bridge between San Francisco and Oakland.

And a major alteration to put it mildly: the infamous Embarcadero!

[kkt]

I'd say the Bay Bridge between San Francisco and Oakland.

Yes: https://www.aaroads.com/forum/index.php?topic=16239.msg2087141#msg2087141

And a major alteration to put it mildly: the infamous Embarcadero!

Alterations, not destruction.  And that's a viaduct, not a bridge.