Bridges that were designed to carry no traffic

[kphoger]

What bridges were built for reasons other than carrying traffic of any kind–not pedestrian, rail, vehicle, or otherwise?

I'm not sure if this counts as a bridge, but this in downtown Dallas was built for the sole purpose of carrying electrical conduit across the freeway.

And how common is it for a pipeline to get its own truss?

[BrianP]

I'm not exactly sure what this carries over I-95 in MD. (A conveyor?)  But it's not carrying any traffic.
https://goo.gl/maps/jDQWGzX7B41V5Ye89

[kphoger]

I'm not exactly sure what this carries over I-95 in MD. (A conveyor?)  But it's not carrying any traffic.
https://goo.gl/maps/jDQWGzX7B41V5Ye89

Yeah, that looks like a mining conveyor.

[CtrlAltDel]

I-40 at the Colorado River has a few pipeline bridges, if that's along the lines of what you're looking for:

[Max Rockatansky]

I-40 at the Colorado River has a few pipeline bridges, if that's along the lines of what you're looking for:

That's former US 66, it was converted to pipeline usage.

[CtrlAltDel]

I-40 at the Colorado River has a few pipeline bridges, if that's along the lines of what you're looking for:

That’s former US 66, it was converted to pipeline usage.

Well, then it's been redesigned to carry no traffic. 

More seriously, though, the image shows three pipeline bridgelike contraptions, and I don't think that all three were US-66. I admit, though, that I didn't look anything up here, and so I might very well be wrong.

[Max Rockatansky]

I-40 at the Colorado River has a few pipeline bridges, if that's along the lines of what you're looking for:

That's former US 66, it was converted to pipeline usage.

Well, then it's been redesigned to carry no traffic. 

More seriously, though, the image shows three pipeline bridgelike contraptions, and I don't think that all three were US-66. I admit, though, that I didn't look anything up here, and so I might very well be wrong.

You are correct, there is two standalone pipeline bridge structures that was designed from the onset as such.  I only know the Colorado Arch Bridge so well because it is a rare example of a classic piece of highway not being demolished or left to rot out in the Mojave:

https://flic.kr/p/RVAj7V

https://flic.kr/p/RVAiLK

[ethanhopkin14]

Makes me think of this or this.

[Big John]

I-376 in Pittsburgh has a bridge over it whose purpose is to collect falling concrete from the crumbling arch bridge above it.

[kphoger]

Makes me think of this or this.

Crazy that the first link points to a suspension, whereas the second points straight down at the pavement.

[US 89]

There is a small suspension bridge carrying a couple pipelines across the Malad River east of Garland, Utah.

I-215 in Salt Lake City has several pipeline bridges in the sunken freeway section, along with a couple carrying some more substantial water courses. This one, for example, carries Little Cottonwood Creek.

There are also a couple bridges carrying mining conveyor belts/pipelines near the Kennecott copper mine on the west side of the valley. Here's one on SR 209 in Copperton and another substantial one across SR 201 west of Magna.

[kphoger]

This one, for example, carries Little Cottonwood Creek.

Now, that's awesome!

[lepidopteran]

On I-285 in Atlanta, I think there was a temporary bridge conveyor for carrying fill dirt and/or aggregate over the highway.  This was for construction of the fifth runway at ATL airport.

Honorable mention goes to this sinuous, enclosed viaduct that runs under I-670 in Columbus, OH.  It connects two pharmaceutical facilities, but I'm not sure if it's a conveyor or just a walkway (or both).

Don't forget the wildlife crossings, one of which is on I-78 in Union County, NJ.  These are starting to appear out west and elsewhere around the world.

I'm not sure, but are there any freeways near airports with bridges whose sole purpose is to stage runway approach lights?

[SkyPesos]

Ancient Roman aqueducts

[NE2]

http://en.wikipedia.org/wiki/Grand_Tower_Pipeline_Bridge

I'm not sure, but are there any freeways near airports with bridges whose sole purpose is to stage runway approach lights?

http://www.google.com/maps/@27.9588363,-82.5421096,3a,75y,274.92h,92.56t/data=!3m6!1e1!3m4!1sQaBF2R-Ia-WlEASwk4-EIA!2e0!7i16384!8i8192

[US 89]

I'm not sure, but are there any freeways near airports with bridges whose sole purpose is to stage runway approach lights?

Atlanta has an example of that as well.

[Big John]

The overhead gantries are called sign bridges.

[index]

https://www.google.com/maps/@64.1564823,-145.8508885,3a,60y,8.64h,91.73t/data=!3m6!1e1!3m4!1sZEz94DpsmDPtQl3laNNXEw!2e0!7i13312!8i6656

There's the bridge that carries the Alaska Pipeline across the Tanana River, near Big Delta.

[Rothman]

The Martin Tipple (at least that's what my relatives called it...wasn't really in Martin), now defunct and mostly demolished, had coal chutes over KY 122.  You could hear coal going through them when driving underneath.

[kphoger]

Some of these (in my own OP as well) are really more just suspensions than actual bridges.

(Also, I'd call wildlife crossings "traffic".)

[Georgia]

Atlanta airport used to have a 2nd approach light bridge over 285 and its C/D lanes, but took it down about 7 years ago. 

[Bitmapped]

Bridges for mine conveyance are pretty common in mining areas. This conveyor near Bobtown, PA has been removed since this GMSV image: https://goo.gl/maps/DoxHUrmp7P72DVXw9

There is (was?) a large suspension bridge carrying coal over WV 103 to a prep plant near Gary, WV: https://goo.gl/maps/jZM18tiXRGo8Nqui7

In Canton, OH, there is a bridge for a water or sewer line over US 30/US 62: https://goo.gl/maps/yGzfd3x7EM8VdcUi7 I presume the lines predates the freeway when there used to be a street on the path of the pipe.

Yeager Airport in Charleston, WV has a large bridge over a ravine carrying approach lighting: https://goo.gl/maps/5Us2vY95pqK1MNJ6A

[ethanhopkin14]

I'm not sure, but are there any freeways near airports with bridges whose sole purpose is to stage runway approach lights?

Atlanta has an example of that as well.

San Antonio.

[roadman65]

In Portland, OR there is a cable stay bridge built across the River in Downtown only to carry light rail.

[kphoger]

... not pedestrian, rail, vehicle, or otherwise?

In Portland, OR there is a cable stay bridge built across the River in Downtown only to carry light rail.