Houston Ship Channel Bridge on Sam Houston Tollway

[roadman65]

I saw the bridge that carries the Sam Houston Tollway over the Houston Ship Chanel.  Its very tall and built with a box girder and looks very impressive to the eye.

Yet, I hear that the current structure is going to be replaced in 2021 with a cable stayed bridge.  Isn't this current structure pretty much brand new or at least a couple decades old?  Why would the Texas Tollway Commission (or whatever the agency is that owns it) wants to replace it so soon?

[Chris]

More info here: https://www.aaroads.com/forum/index.php?topic=15429.0