San Antonio: North Loop 1604 expansion now planned to be 4-1H-1H-4

[MaxConcrete]

http://ftp.dot.state.tx.us/pub/txdot/ppd/0000003693/pre-rfq-presentation.pdf

Consultant solicitation
https://www.txdot.gov/business/consultants/architectural-engineering-surveying/meetings/120318.html

Note that schematics on the main page are the original, now obsolete design which was 2-2T-2T-2 (T=tolled). According to the presentation "Schematic re-development is underway with AECOM".

Brief history: Loop 1604 is currently in its original 2x2 configuration, and for a very long time plans have been discussed and developed to add four tolled lanes (and no new general-purpose lanes). But, lucky for San Antonio, the project was delayed so long that now the political climate has shifted, and according to presentation the four new lanes will be general-purpose non-tolled. The cross-section view also shows two "HOV/Special purpose lanes", one in each direction, for a 4-1H-1H-4 configuration.

The presentation says construction begins in 2021. San Antonio better hope they can actually get it done this time, because you never know, the pendulum might swing back in favor of toll lanes.

[Chris]

According to that presentation they have a funding gap of almost $ 500 million for this project.

I'm wondering, where are they going to get all that money to construct these large urban freeway projects without a toll component?

[Bobby5280]

The presentation says construction begins in 2021. San Antonio better hope they can actually get it done this time, because you never know, the pendulum might swing back in favor of toll lanes.

Politics is one thing. But math is a harder, more truthful reality. How much will this project's costs rise between now and 2021? How much more of a financial gap will there be in available fuel tax-based funding versus how much the road costs at that time?

No one really likes toll roads at all. For some projects the notion of building it as a toll road will make the difference between it being built or not built at all.

I am glad they're re-designing the road as a 4-1H 1H 4 facility. I can't stand the 2-2T-2T-2 setups, like the north part of I-820 in Fort Worth for example. The road eats up a lot of extra real estate but has limited traffic capacity. A "free" road in the same space could have 6 or 7 lanes in each direction.

[Plutonic Panda]

The presentation says construction begins in 2021. San Antonio better hope they can actually get it done this time, because you never know, the pendulum might swing back in favor of toll lanes.

Politics is one thing. But math is a harder, more truthful reality. How much will this project's costs rise between now and 2021? How much more of a financial gap will there be in available fuel tax-based funding versus how much the road costs at that time?

No one really likes toll roads at all. For some projects the notion of building it as a toll road will make the difference between it being built or not built at all.

I am glad they're re-designing the road as a 4-1H 1H 4 facility. I can't stand the 2-2T-2T-2 setups, like the north part of I-820 in Fort Worth for example. The road eats up a lot of extra real estate but has limited traffic capacity. A "free" road in the same space could have 6 or 7 lanes in each direction.

Or instead of going all out with concrete barriers they could have those flexible plastic barriers(I can't remember what they're called) that would save an tremendous amount of money and a lot of space. I'm with you on the 2T-2F setup anyways. Or you could just use paint to separate the lanes and ticket people that are caught cheating.

[froggie]

A "free" road in the same space could have 6 or 7 lanes in each direction.

But would be a lot more inefficient once you get beyond 4-5 lanes on one carriageway.  Freeway lanes lose efficiency and capacity once you go beyond that threshold.

For a case-study on flexible bollards (basically what Plutonic Panda was referring to), look at the Virginia portion of the D.C. Beltway.

[In_Correct]

I prefer at least two tolled lanes in each direction just as at least two free lanes in each direction and also continuous frontage roads with at least two lanes in each direction in addition to the slip ramps.

A "free" road in the same space could have 6 or 7 lanes in each direction.

But would be a lot more inefficient once you get beyond 4-5 lanes on one carriageway.  Freeway lanes lose efficiency and capacity once you go beyond that threshold.

For a case-study on flexible bollards (basically what Plutonic Panda was referring to), look at the Virginia portion of the D.C. Beltway.

Or to start out with perhaps those huge dome shaped bump things that are slightly larger than the button reflectors. I do not know the name of them but they are probably 6 inches in height and are meant to be dividers.

As for the maximum efficiency of carriageways, perhaps Barrier Transfer is useful. At that point, passenger rail should also be considered.

[rte66man]

 

I prefer at least two tolled lanes in each direction just as at least two free lanes in each direction and also continuous frontage roads with at least two lanes in each direction in addition to the slip ramps.

A "free" road in the same space could have 6 or 7 lanes in each direction.

But would be a lot more inefficient once you get beyond 4-5 lanes on one carriageway.  Freeway lanes lose efficiency and capacity once you go beyond that threshold.

For a case-study on flexible bollards (basically what Plutonic Panda was referring to), look at the Virginia portion of the D.C. Beltway.

Or to start out with perhaps those huge dome shaped bump things that are slightly larger than the button reflectors. I do not know the name of them but they are probably 6 inches in height and are meant to be dividers.

Botts dots on steroids? 

[In_Correct]

What ever those things are, they are much larger than Bott Dots. They are the same height as Parking Stops or Wheel Stops (which could also be used as barriers) but are dome shaped and are placed next to each other forming a line not meant to be driven over.

I have been searching for pictures. I have not found any but remember them. It is possible that they have been phased out a long time ago.

[wxfree]

I think you mean these.  TxDOT's Waco district seems to like them.  They use them at intersections to simulate curbs where curbs don't exist.  I don't know what they're called.  I looked through construction plans to see if there are any references to them, and didn't find any.  Either they're being phased out, or they're added without being in the official plans.

https://www.google.com/maps/@32.0806312,-97.5510448,3a,60y,318.09h,86.71t/data=!3m6!1e1!3m4!1s1Wyc8XxWC-wnzPvYhYM-4w!2e0!7i13312!8i6656?hl=en

[djlynch]

I thought of something like these that the City of Austin has started using to separate some bike lanes, pedestrian refuges, etc. from vehicular traffic. They're two or three inches high at the outside edge and another two or three inches higher at the center.

https://www.google.com/maps/@30.2018785,-97.7546605,3a,20.4y,188.81h,79.13t/data=!3m6!1e1!3m4!1stqopSZSncIZku4pcAIYXBw!2e0!7i13312!8i6656

[In_Correct]

I thought of something like these that the City of Austin has started using to separate some bike lanes, pedestrian refuges, etc. from vehicular traffic. They're two or three inches high at the outside edge and another two or three inches higher at the center.

https://www.google.com/maps/@30.2018785,-97.7546605,3a,20.4y,188.81h,79.13t/data=!3m6!1e1!3m4!1stqopSZSncIZku4pcAIYXBw!2e0!7i13312!8i6656

That's It! 

Those are what I have seen before. But I have also seen them forming a line not spaced out but touching each other.

[MaxConcrete]

Schematics are online for the public meeting which took place this week
https://www.txdot.gov/inside-txdot/get-involved/about/hearings-meetings/san-antonio/090519.html

Observations
* A five level interchange is planned at I-10, with some very long elevated connection ramps. Six ramps are in the range of 1.8 to 2.0 miles long.
* The frontage roads at ground level at the I-10 interchange feature a strange "continuous flow partial roundabout", which eliminates traffic signals
* Design standards are compromised on a long section in the middle, with 11-foot-wide lanes and no interior shoulder. TxDOT has compromised standards in Houston and Dallas, so now it's San Antonio's turn
* Existing bridges are retained on most of the project and widened for the new lanes

[Bobby5280]

God, I hate narrow lanes. Oh. Sorry, everyone knew that already. I'll go back to sleep.


Seriously though, 11' wide lanes are only going to ask for very expensive construction remedies in the future. Too many vehicles are going to trade paint with that claustrophobic narrow lane arrangement.

[Plutonic Panda]

I was wondering how long it would take you to point that out and then I looked down 

I agree though. This seems to be TxDOTs mantra. Squeeze em where we can. LOL

[Chris]

Schematics are online for the public meeting which took place this week
https://www.txdot.gov/inside-txdot/get-involved/about/hearings-meetings/san-antonio/090519.html

Observations
* The frontage roads at ground level at the I-10 interchange feature a strange "continuous flow partial roundabout", which eliminates traffic signals

Is this a first in Texas?

[-- US 175 --]

Schematics are online for the public meeting which took place this week
https://www.txdot.gov/inside-txdot/get-involved/about/hearings-meetings/san-antonio/090519.html

Observations
* The frontage roads at ground level at the I-10 interchange feature a strange "continuous flow partial roundabout", which eliminates traffic signals

Is this a first in Texas?

I would guess.  It's the first I've seen of it.  It'll probably be quite the driver learning curve, like DDIs and SPUIs (and likely even roundabouts in some places) have been.

[The Ghostbuster]

Are there plans to eventually make the entire 1604 beltway completely freeway (no at-grade intersections or driveways)?

[Bobby5280]

It certainly seems that way. Aside from the new construction going on with the West quadrant of Loop 1604, just about all the older segments have had swaths of cleared ROW available for future expansion off to the left or right of the existing 2 lane road. What seems a little iffy though is whether 4 lane upgrades on the South and East sides will be as full freeways or as expressway segments with at-grade intersections.

Obviously major intersections along Loop 1604 (such as Palo Alto Rd or US-281 on the South side) will be built as freeway style diamond exits.  But the segments in between could still be stuck with at-grade intersections. It looks most of these upgrade-able segments of Loop 1604 have about 220 feet of ROW. That's enough for a basic 4 lane freeway. But it's not enough for a freeway flanked by frontage roads. It takes at least a good 300 foot wide ROW to fit something like that. On the bright side the 2 lane sections of Loop 1604 currently run through pretty rural, sparsely populated areas. It probably wouldn't be all that relatively difficult to expand the ROW a good bit more as needed. Not too many properties to acquire and clear.

[sprjus4]

Don't necessarily agree with the substandard designs, but I can see why they're being used, and overall I'm just glad to see this finally happening. The entire northern arc of 1604 is a mess, especially the I-10 interchange, which is way beyond substandard for today's traffic needs.

This, along with the under construction 281 freeway upgrade, the proposed I-35 Express Lanes, and other mega projects to come in the future, is definitely a good thing for the area, and the best part about all of it is that none of these multi-billion dollar expansions include 1 cent of tolls.

One question I have - why was the new freeway segments on the west side connecting to US-90 built with only 4-lanes? That area is growing rapidly, and someone with any common sense should realize that stretch is going to need at least 6 lanes in 20 years. I've driven on it a few times since it's opened, and it's already well used, and only going to grow as the west side expands.

[Bobby5280]

Loop 1604 isn't freeway quality where it crosses US-90 on the West side of San Antonio. There is a new direct connect flyover ramp from SB Loop 1604 to EB US-90. But Loop 1604 still goes through a pair of traffic lights on either side of the US-90 interchange.

Still, it is kind of odd that so much of the freeway portion of Loop 1604 is only 2 lanes in each direction (particularly out on the West side). I also agree the cloverleaf interchange with I-10 on the NW side of San Antonio badly needs to be upgraded to a modern 4 level stack. The C/D lanes might alleviate some of the conflicts, but it's still a bottleneck. Also annoying, a few of the stack interchanges San Antonio does have feature ramps with tight turns and lower speed limits. It's 45mph on the Loop 1604 ramps with US-281. There's a 30mph limit on I-410 to I-10 on the NW side of San Antonio. Might as well be driving through a cloverleaf.

[sprjus4]

Loop 1604 isn't freeway quality where it crosses US-90 on the West side of San Antonio. There is a new direct connect flyover ramp from SB Loop 1604 to EB US-90. But Loop 1604 still goes through a pair of traffic lights on either side of the US-90 interchange.

The point was that the freeway was just extended out to the US-90 interchange and terminates at the traffic signal. It's a four-lane freeway just north of the signal.

The flyover helps to handle the major movement, and provides an all freeway connection for that major movement, bypassing the traffic signals.

Also annoying, a few of the stack interchanges San Antonio does have feature ramps with tight turns and lower speed limits. It's 45mph on the Loop 1604 ramps with US-281. There's a 30mph limit on I-410 to I-10 on the NW side of San Antonio. Might as well be driving through a cloverleaf.

I agree, you usually would expect higher speeds, though some of the older ones, like I-37 / I-410 for example, lack that, and are only 30 - 35 mph.

That's not a large priority though - the point of having a stack, even with slow speeds, over a cloverleaf is to eliminate weaving and separate all traffic movements, which the low-speed ones still do.

[sprjus4]

Another question regarding the upcoming 10-lane widening - will the speed limit, once the project is completed, be reverted back to 70 mph, or will it permanently be lowered to 60 or 65 mph?

[Anthony_JK]

It certainly seems that way. Aside from the new construction going on with the West quadrant of Loop 1604, just about all the older segments have had swaths of cleared ROW available for future expansion off to the left or right of the existing 2 lane road. What seems a little iffy though is whether 4 lane upgrades on the South and East sides will be as full freeways or as expressway segments with at-grade intersections.

Obviously major intersections along Loop 1604 (such as Palo Alto Rd or US-281 on the South side) will be built as freeway style diamond exits.  But the segments in between could still be stuck with at-grade intersections. It looks most of these upgrade-able segments of Loop 1604 have about 220 feet of ROW. That's enough for a basic 4 lane freeway. But it's not enough for a freeway flanked by frontage roads. It takes at least a good 300 foot wide ROW to fit something like that. On the bright side the 2 lane sections of Loop 1604 currently run through pretty rural, sparsely populated areas. It probably wouldn't be all that relatively difficult to expand the ROW a good bit more as needed. Not too many properties to acquire and clear.

The south and southeast segments of Loop 1604 from I-35 east and north to I-10 do have potential as part of the SH Toll 130 bypass, though IIRC, the 330 bypass is now signed along I-410 and I-10. The western segment from US 90 west should be expandable as well, with proper direct connections.

The rest, though? I'd say do like the Grand Parkway in Houston: either build the frontage roads with enough ROW within for the future mainlanes and overpasses, or build a 4-lane divided with temporary at-grade intersections with upgradability down the road. Either way, no rush to complete as of yet.

[Modded by me to fix my grievous error.]

[sprjus4]

The south and southeast segments of Loop 1604 from I-35 east and north to I-10 do have potential as part of the SH Toll 130 bypass, though IIRC, the 130 bypass is now signed along I-410 and I-10. The western segment from US 90 west should be expandable as well, with proper direct connections.

FTFY

[Anthony_JK]

The south and southeast segments of Loop 1604 from I-35 east and north to I-10 do have potential as part of the SH Toll 130 bypass, though IIRC, the 130 bypass is now signed along I-410 and I-10. The western segment from US 90 west should be expandable as well, with proper direct connections.

FTFY

Brain snapped a bit there. Thanks.