AARoads Forum

Regional Boards => Mid-South => Topic started by: thisdj78 on November 28, 2021, 10:56:10 PM

Title: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: thisdj78 on November 28, 2021, 10:56:10 PM
I was riding along SH130 and just now noticed that the Northbound bridge over US79 is significantly longer than the Southbound bridge. Any thoughts on why that is? Link below:

https://goo.gl/maps/7ZeiD8TpSU7vUMm27
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: Bobby5280 on November 28, 2021, 11:35:52 PM
The longer bridge must have been built to accommodate a directional ramp running directly from US-79 to TX-130, such as a Westbound US-79 to Southbound TX-130 ramp. The Northbound TX-130 frontage road is depressed under US-79 movements and the railroad track running parallel to it. A directional ramp in the movement I described could thread under the Northbound TX-130 lanes and merge into Southbound TX-130 from the left. Of course that kind of thing is frowned upon in modern freeway standards, which might explain one reason why direct connect ramps at this interchange have not been built at all. TX-130/US-79 is a "volleyball" for the time being.
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: thisdj78 on November 29, 2021, 11:47:23 AM
The longer bridge must have been built to accommodate a directional ramp running directly from US-79 to TX-130, such as a Westbound US-79 to Southbound TX-130 ramp. The Northbound TX-130 frontage road is depressed under US-79 movements and the railroad track running parallel to it. A directional ramp in the movement I described could thread under the Northbound TX-130 lanes and merge into Southbound TX-130 from the left. Of course that kind of thing is frowned upon in modern freeway standards, which might explain one reason why direct connect ramps at this interchange have not been built at all. TX-130/US-79 is a "volleyball" for the time being.

That was my initial thought but the NB bridge is the same height as the SB bridge so it seems like there wouldnít be enough clearance.

Iím wondering if itís related to rail? I vaguely remember reading somewhere that the median on 130 was designed to allow for future commuter rail lines. The rail along US79 is currently used by Amtrak.
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: thisdj78 on November 29, 2021, 06:38:47 PM
I think I found the answer from a construction company website:

The alignment and proposed median width have been designed to accommodate future transportation needs such as general multi-purpose lanes, high-occupancy vehicle (HOV) facilities, and light rail transit.

https://www.balfourbeattyus.com/our-work/project-portfolio/state-highway-130

Öand this which would explain a tie into the existing railroad:

There has also been discussion about including a future freight railroad bypass in the SH 130 corridor. Freight train traffic, like its counterpart truck traffic, has also increased substantially in the region, and the existing railways go right through the center of the cities in the I-35 corridor, causing recurring congestion problems. A railway bypass along SH 130 would help reduce congestion in the cities on the corridor and would also free the existing rail line for a long-planned San Antonio-Austin commuter rail line.

http://www.texashighwayman.com/sh130.shtml

Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: bwana39 on December 02, 2021, 12:57:29 AM
There seem to be several answers. The answer is they built a shorter berm for the later built one. Perhaps it was because they planned to run something under it, perhaps a bridge was either more sturdy or cheaper to build than berm at the particular time or place..
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: thisdj78 on December 02, 2021, 06:23:37 AM
There seem to be several answers. The answer is they built a shorter berm for the later built one. Perhaps it was because they planned to run something under it, perhaps a bridge was either more sturdy or cheaper to build than berm at the particular time or place..

I believe both bridges were built at the exact same time, so I donít know if it would be for cost reasons.
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: longhorn on March 25, 2022, 02:44:41 PM
https://www.google.com/maps/@30.5335457,-97.576472,3a,75y,24.28h,79.79t/data=!3m6!1e1!3m4!1sZ0z3XMvlwIkGgCk2_r6ZLQ!2e0!7i16384!8i8192

This lends credence to the direct ramp idea.

130 is a strange bird. Why the expansive median across from the Tesla Factory down by hwy 71?
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: Echostatic on March 25, 2022, 07:49:33 PM
130 is a strange bird. Why the expansive median across from the Tesla Factory down by hwy 71?

TxDOT uses the median there as a storage yard.
Title: Re: Question on 130 Toll bridges over US 79: Why is NB bridge longer than SB bridge?
Post by: thisdj78 on March 26, 2022, 01:48:50 PM
https://www.google.com/maps/@30.5335457,-97.576472,3a,75y,24.28h,79.79t/data=!3m6!1e1!3m4!1sZ0z3XMvlwIkGgCk2_r6ZLQ!2e0!7i16384!8i8192

This lends credence to the direct ramp idea.

130 is a strange bird. Why the expansive median across from the Tesla Factory down by hwy 71?

I remember reading several years ago that they set aside that area for two possible reasons:

A) If they build a regional commuter rail line in the median, that would be where the ďAustinĒ station is location

Or

B) A rest area/travel & gas center