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 (https://www.tpr.org/texas/2022-05-11/ground-broken-on-i-35-double-decker-project) and construction on the $1.5 billion project will last until 2027.
(https://i.imgur.com/PUkM3V1.jpg)
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
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.
https://www.aaroads.com/forum/index.php?topic=24909.0
Quote from: Plutonic Panda on May 12, 2022, 01:06:14 AM
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?
Quote from: Plutonic Panda on May 12, 2022, 01:06:14 AM
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.
The winning proposer for the second phase of work was announced today
https://ftp.txdot.gov/pub/txdot/commission/2023/0525/6-presentation.pdf (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.