I-35 Expansion in San Antonio

[kernals12]

With much less controversy than in Austin, TxDOT is undertaking a massive expansion of I-35 in San Antonio. They're double decking 10 miles of it northeast of I-410 with 3 non-tolled express lanes in each direction. The groundbreaking ceremony was held today and construction on the $1.5 billion project will last until 2027.



Combined with the widening of Loop 1604 from 4 lanes to 10, San Antonio is really going agro on its traffic problems.

It does beg the question though of why they can't do this for I-45 in Houston

[Plutonic Panda]

Is this considered "double decking?"  To me they're just adding elevated express lanes. Double decking would technically be placing a deck over the existing highway.

Either way this is an excellent project. I wish they'd do this on US-101 from downtown LA to Topanga Canyon.

[sprjus4]

https://www.aaroads.com/forum/index.php?topic=24909.0

[longhorn]

[kphoger]

Is this considered "double decking?"  To me they're just adding elevated express lanes. Double decking would technically be placing a deck over the existing highway.

Either way this is an excellent project. I wish they'd do this on US-101 from downtown LA to Topanga Canyon.

Aren't the elevated structures going to be "a deck over the existing" frontage roads?

[jgb191]

Is this considered "double decking?"  To me they're just adding elevated express lanes. Double decking would technically be placing a deck over the existing highway.

Either way this is an excellent project. I wish they'd do this on US-101 from downtown LA to Topanga Canyon.

Yeah it's still considered a double-deck because the elevated lanes will still fly directly above the ground lanes.  The difference between this and the original double deck sections of I-10 between downtown and I-410 is that the upper level of the upcoming I-35 section is limited exclusively to express traffic (nonstop from downtown to the county line) and lower levels are for local traffic who intend to enter the freeway and exit after a short distance.  The original sections on I-10 had on and off ramps from both levels.  Also the original I-10 eastbound and westbound upper levels are closer apart (if you flew over it in a helicopter, you couldn't easily see the lower level); whereas on the new I-35 section there will be a considerably wider gap between the northbound and southbound upper levels that will expose the lower level even from a birds-eye view.

[MaxConcrete]

The winning proposer for the second phase of work was announced today
https://ftp.txdot.gov/pub/txdot/commission/2023/0525/6-presentation.pdf

This is the blue section shown on page 3

Winning bid:
Lone Star Constructors (Flour, Austin Bridge & Road)
$700 million + $18.7 million for 15 years of maintenance

Estimated cost: $810.3 million  (This was probably recently updated to reflect recent inflation.)


Observations

• This is the first design-build project to go under estimate for a while. However, the estimate may be inflated to current costs and I don't know what the estimate was 6 or 12 months ago. US 290 in Austin, I-20 and 820 in Fort Worth and I-635 in Austin were all well over estimated cost.
• This will connect to the elevated express lanes already underway on the adjacent northeast section.
• Completion in Spring 2028
• The green sections on the map still remain to be done. They will be traditional design-bid-build.

[Chris]

https://twitter.com/TxDOTSanAntonio/status/1790468171381531015

[DNAguy]

I feel as if there was a missed opportunity with this project in tying in the Wurzbach Parkway into this somehow with a couple of direct connectors at Thousand Oaks. There seems to be enough ROW now.... but likely won't be in the near future.

I35N to Wurzbach westbound and Wurzbach eastbound to I35S would probably be enough to handle the current traffic patterns.

Oh well I guess.