Corpus Christi I-37 questions

[longhorn]

https://www.google.com/maps/@27.7980444,-97.4115177,3a,46.6y,77.87h,85.76t/data=!3m6!1e1!3m4!1sBsn3FBJMSW8rCteF4KVRlg!2e0!7i13312!8i6656

So what construction is going in Corpus Christi? I-37 being widened? Is this the interchange for the new Harbor bridge? What will happen to the old Harbor Bridge?

[sprjus4]

https://www.google.com/maps/@27.7980444,-97.4115177,3a,46.6y,77.87h,85.76t/data=!3m6!1e1!3m4!1sBsn3FBJMSW8rCteF4KVRlg!2e0!7i13312!8i6656

So what construction is going in Corpus Christi? I-37 being widened? Is this the interchange for the new Harbor bridge? What will happen to the old Harbor Bridge?

It's the interchange construction for the new Harbor Bridge. The new bridge is being built on new location directly across from TX-286 (Crosstown Expwy) which will result in one four-way interchange between I-37, TX-286, and US-181, instead of the two disconnected interchanges that exist today. TX-286 and US-181 will be one continuous freeway when completed.

The old bridge will be demolished once the new bridge is opened to traffic fully.

Here you can see bridge construction well underway on the northern tie in - https://www.google.com/maps/@27.823763,-97.3904433,3a,75y,225.31h,81.07t/data=!3m6!1e1!3m4!1sQqYzmFJZHxMRuH6r2wY_0w!2e0!7i13312!8i6656

And from the existing bridge - https://www.google.com/maps/@27.813782,-97.3946706,3a,75y,17.43h,80.93t/data=!3m6!1e1!3m4!1sSzmImMewkhTgNLlx3MXjGA!2e0!7i13312!8i6656

Schematics of the final interchange configuration (the new bridge is in orange) -

[Bobby5280]

The New Harbor Bridge will have a span of 1661 feet, making it the longest cable stay span in North America. The bridge will have 6 lanes, plus shoulders and a pedestrian walkway.

[sprjus4]

The New Harbor Bridge will have a span of 1661 feet, making it the longest cable stay span in North America. The bridge will have 6 lanes, plus shoulders and a pedestrian walkway.

It still makes me wonder why aren't they building the bridge to be able to accommodate a future 4th lane each way? You'd think on a massive project like this it would be designed for future expansion.

[Bobby5280]

I'm sure cost had to be a factor.

[sprjus4]

I'm sure cost had to be a factor.

Well it's going to sure cost them a lot more in the future if they ever decide to widen it (is that even possible?)

In Hampton Roads, they originally were only going to add a 3-lane tunnel to the HRBT (Hampton Roads Bridge Tunnel) expansion, but they decided it would be more wise to spend more money now and simply add two 2-lane tunnels, a total of 4-lanes instead of 3. Cost more now, will save significantly amounts of money later.

[Bobby5280]

I'm guessing there is a limit to just how much road a modern cable stay span bridge can carry, especially one with a really long span over 1600' in length. If they increased the number of lanes and traffic capacity further TX DOT probably would have been looking at building twin bridges rather than just one.

[In_Correct]

A new bridge with three lanes in each direction could be twinned, meaning six lanes in each direction. 

By the time that they build a twin bridge, six lanes in each direction might not be enough.

[Bobby5280]

Twin bridges is a trend in some of the larger metro areas. North of NYC the new Governor Cuomo Bridge (which replaced the Tappan Zee Bridge) is a large capacity twin bridge. I think one of the bridges has 8 or 10 lanes. But the actual cable stay span portion of the bridge is relatively short compared to this new bridge in Corpus Christi. The same goes for the new East span of the Oakland Bay Bridge. That has 10 lanes, plus ample shoulders and a 2-lane bike/jogging path. But it's effectively 2 bridges running parallel to each other. The cable stay portion is effectively one bridge, but it's a very heavy duty structure running a fairly brief length. The new Goethals twin bridges in Staten Island have 3 lanes plus ample shoulders on each bridge.