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The Great Lafayette I-49 Connector "Debate"

Started by Anthony_JK, March 26, 2014, 02:55:46 PM

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Anthony_JK

OK....here's that new thread I promised.

This is taken directly from this thread:

https://www.aaroads.com/forum/index.php?topic=11839

When we last left, me and jpnv were arguing about his alternate proposal for connecting the proposed I-49 freeway with Johnston St., while severing the existing connection between Johnston and Louisiana Avenue, which meet at the current Evangeline Thruway. For reference, here's his rendition of his proposal:





And once again for a comparison, here's the official FHWA/LaDOTD rendering of the approved path for the I-49 Connector as stated in the 2003 ROD:





As you can plainly see, the proposed design approved by LADOTD allows for far better access to the downtown area, severs fewer streets, meets all current design standards, and would adequately seperate freeway from local traffic using the existing Evangeline Thruway. It is also the alignment that was approved by the local MPO, which consists of city representatives.

As for jpnv's proposal...where do I begin?

First, his direct connectors  with Johnston St. would entail sharp curves and steep grades well in excess of current design standards, because in order for the directional ramps to work and cross over the BNSF railine that would parallel his routing, the ramps would have to be elevated as high as 40-50 feet above grade level. That would neccesitate not only cutting off the Cypress/Garfield St. intersection with Johnston St., defeating the entire purpose of his proposal of accessing downtown, but also introduce more extraneous costs. Plus, his connectors would completely take out the Rosa Parks Transportation Center, which serves as the current Lafayette City Bus terminal as well as the terminal for Amtrak, and also the actual building where the MPO resides.

Second, he doesn't even provide complete connectors to Louisiana Ave, only an off ramp from N-bound I-49 weaving with another ramp that would access Johnston St. He even manages to get the off-ramp connections between Johnston and I-49 wrong.

Third, his proposal looks like he merely grafted a pair of lines representing the I-49 mainlaines onto a grid and added slip ramps in places...just because. For example, he eliminates Second Street, which is one-way westbound and which serves as the first entry into downtown Lafayette from the Evangeline Thruway...but he places the southbound exit ramp from I-49 onto Third Street....which is one-way EASTBOUND, away from downtown. He also places the onramp from Evangeline Thruway to I-49 just north of Simcoe St, directly adjacent to St. Genevieve Catholic Church...a deliberate non-starter that the curvature of the LADOTD proposal was directly created to avoid. (St. Genevieve is part of the Sterling Grove Historicall District, which lies just east of the Evangeline Thruway.)

Like I said in the earlier thread, he has every right to his opinions and his proposals, and I have just as much right to critique them and defend the MPO and LADOTD's proposal. But, you can judge for yourself who's closer to the truth.


longhorn

Whats the timeframe on the project beginning. I wander how many blocks will be needed for this expressway through down town. While they are at it take out the dozen or so stoplights from the airport south.

nolia_boi504

Stupid question but why isn't I-49S following 90 in the area shown in your sketch? It seems like if the land between the two sides of the thruway were bought out, a highway can be built in the middle and the existing Thwy lanes can remain as Texas style feeders.

It seems as if the majority of the Lafayette portion of I-49S has enough room to be built this way. But whether the feeders are necessary or not is beyond me.

Nexus 5


NE2

Quote from: nolia_boi504 on March 26, 2014, 04:43:52 PM
Stupid question but why isn't I-49S following 90 in the area shown in your sketch? It seems like if the land between the two sides of the thruway were bought out, a highway can be built in the middle and the existing Thwy lanes can remain as Texas style feeders.
I see far fewer properties next to the railroad than between the one-way pair. Who knows if the separate interchanges are necessary or if they can just use the existing one-way pair for access.
pre-1945 Florida route log

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Urban Prairie Schooner

Quote from: nolia_boi504 on March 26, 2014, 04:43:52 PM
Stupid question but why isn't I-49S following 90 in the area shown in your sketch? It seems like if the land between the two sides of the thruway were bought out, a highway can be built in the middle and the existing Thwy lanes can remain as Texas style feeders.

It seems as if the majority of the Lafayette portion of I-49S has enough room to be built this way. But whether the feeders are necessary or not is beyond me.

Nexus 5



It was deemed less destructive to the urban fabric to route I-49 along the railroad corridor than within the Evangeline Thruway couplet. There is more open land there and the land use is predominately industrial, while Evangeline Thruway passes through a more residential area.

Anthony_JK

Quote from: nolia_boi504 on March 26, 2014, 04:43:52 PM
Stupid question but why isn't I-49S following 90 in the area shown in your sketch? It seems like if the land between the two sides of the thruway were bought out, a highway can be built in the middle and the existing Thwy lanes can remain as Texas style feeders.

It seems as if the majority of the Lafayette portion of I-49S has enough room to be built this way. But whether the feeders are necessary or not is beyond me.

Nexus 5



The median between the Evangeline Thruway couplet from Simcoe to 14th/Taft Streets is very highly developed; while the segment immediately to the west of that area is more commercially driven, and the path of a former rail yard.

There was a proposal that would have followed the median of the Thruway for its entire extent, but it was rejected, mostly because the approved proposal allowed for a more gentle curvature meeting design standands, was further away from the St. Genevieve Catholic Church and Sterling Grove Historical District, and allowed for the improvements in access to downtown through the railroad grade seperations and interchanges provided.

The approved alignment was also the one recommended by the local Lafayette MPO and local officials.

Anthony_JK

Quote from: longhorn on March 26, 2014, 04:38:14 PM
Whats the timeframe on the project beginning. I wander how many blocks will be needed for this expressway through down town. While they are at it take out the dozen or so stoplights from the airport south.

They are restarting the design and ROW acquisition process this year; still awaiting funding for a suitable timeframe for construction.

Anthony_JK

Quote from: NE2 on March 26, 2014, 05:04:36 PM
Quote from: nolia_boi504 on March 26, 2014, 04:43:52 PM
Stupid question but why isn't I-49S following 90 in the area shown in your sketch? It seems like if the land between the two sides of the thruway were bought out, a highway can be built in the middle and the existing Thwy lanes can remain as Texas style feeders.
I see far fewer properties next to the railroad than between the one-way pair. Who knows if the separate interchanges are necessary or if they can just use the existing one-way pair for access.

You could make a case that the interchanges aren't really needed..but they do provide direct access to downtown from north and south, and they would improve traffic flow by adding railroad grade seperations at major arterials.



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