19 proposed I-49 refinements

BackgroundI-49 Lafayette Connector Concept Refinement

Background of the Community Outreach and Concept Refinement Phase

The Context Sensitive Solutions (CSS) process for the I-49 Lafayette Connector began in 2015 with the intent to focus community outreach, discussion, and debate primarily on the CSS design features of the federally approved corridor concept. After speaking with hundreds of community members and agency stakeholders, however, it became very apparent that the community desired a more in-depth discussion and evaluation of potential refinements to the original I-49 Lafayette Connector concept. Several years have passed since the suspension of the last planning/design process and the community has undergone significant change. In response, the DOTD/LCP Team inserted a Concept Refinement phase into the CSS program, lasting approximately 6 months, in order to gather input from the community and the work groups to:

1. Review and discuss the changes that had taken place in the community;

2. Identify potential refinements to the I-49 Connector Concept; and

3. Review those potential refinements from a community and technical perspective, through a three tiered evaluation process, eventually leading to a final refinement concept recommendation.

The refinement concepts and ideas considered during this phase must fall along the approved corridor. A concept or idea could not be considered if it had already been studied in the previous work and determined it should not move forward. After the new Concept Refinement phase is complete, project planning will return to the original CSS program which focused on the CSS design features.

Submitting a Public Comment:

Several avenues are available to submit public comments about the project or the concepts and include:

• Attending public meetings like the one scheduled for April 27, 2016 and filling out a comment card or providing a voice recorded comment at the event.

• Filling out a comment card before or after CSS Committee meetings scheduled over the next several months.

• Sending comments to the project email address at: [email protected]

• Providing comments via the project website at: www.LafayetteConnector.com

Key Features • Single Point Urban Interchanges (SPUI) at Johnston and 2nd/3rd Streets• RR Crossing Grade Separations at Johnston, Jefferson, and 2nd/3rd Streets• 2nd and 3rd Streets realigned to come together at single interchange• Johnston Street realigned to straighten curve and accommodate interchange ramps• Portion of mainline I-49 on embankment between Johnston and 2nd/3rd Street interchanges• Evangeline Thruway serves as a part of overall frontage road system

EXAMPLES OF SIMILAR TRANSPORTATION FEATURES

Elevated Freeway Structure Single Point Urban Interchange (SPUI)

Urban Freeway on Embankment

REFINEMENT CONCEPT - 1ABase Case (I-49 Lafayette Connector Concept, preliminary engineering concept representation of FEIS Selected Alternative and ROD, 2003-2004)

Key Features • Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) replaced with Tight Urban

Diamond Interchanges (TUDI)• RR Crossing Grade Separations at Johnston, Jefferson, and 2nd/3rd Streets• 2nd and 3rd Streets realigned to come together at single interchange• Johnston Street realigned to straighten curve and accommodate interchange ramps • Portion of mainline I-49 on embankment between Johnston and 2nd/3rd Street interchanges• Evangeline Thruway serves as a part of overall frontage road system

REFINEMENT CONCEPT - 1BBase Case (I-49 Lafayette Connector, 2003-2004) Modified


Tight Urban Diamond Interchange (TUDI)

Urban Freeway on EmbankmentElevated Freeway Structure

Key Features • 2nd/3rd Streets Single Point Urban Interchange (SPUI) removed• Johnston Street Single Point Urban Interchange changed to Tight Urban Diamond Interchange (TUDI)• RR Crossing Grade Separation removed at 2nd/3rd Street • RR Crossing Grade Separation at Jefferson Street• Evangeline Thruway remains connected to overall frontage road system• Portion of mainline I-49 on embankment between Johnston and 2nd/3rd Street interchanges


Freeway on Embankment

REFINEMENT CONCEPT - 2ABase Case with Core Area Single Interchange – Johnston Street

Elevated Freeway Structure Tight Urban Diamond Interchange (TUDI)

Key Features • Johnston Street Single Point Urban Interchange (SPUI) removed• 2nd/3rd Street Single Point Urban Interchange changed to Tight Urban Diamond Interchange (TUDI)• RR Crossing Grade Separation removed at Johnston Street/Louisiana Avenue• RR Crossing Grade Separation at Jefferson Street• Evangeline Thruway remains connected to overall frontage road system• Portion of mainline I-49 on embankment between Johnston and 2nd/3rd Street interchanges

REFINEMENT CONCEPT - 2BBase Case with Core Area Single Interchange – 2nd/3rd Street


Freeway on Embankment Elevated Freeway Structure Tight Urban Diamond Interchange (TUDI)

Key Features • Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) changed to function as a split

diamond interchange with connecting road system between half-diamonds: – Johnston/Louisiana will be half-diamond to/from the south – 2nd/3rd Streets will be half-diamond to/from the north

• Connecting roads between interchanges are at-grade and access controlled• Freeway maintained on structure between Johnston and Jefferson Streets


Split Diamond Interchange with Connector Roads At-Grade Connector Road

REFINEMENT CONCEPT - 3ASplit Diamond Interchange with At-Grade Connector Roads

Elevated Freeway

• RR Crossing Grade Separations removed at Johnston and 2nd/3rd Streets

• RR Crossing Grade Separation maintained at Jefferson Street

• Evangeline Thruway remains connected to overall frontage road system

Key Features • Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) changed to function as a split

diamond interchange with connecting road system between half-diamonds: – Johnston/Louisiana will be half-diamond to/from the south – 2nd/3rd Streets will be half-diamond to/from the north

• Connecting roads between interchanges are depressed in open trench • Freeway maintained on structure between Johnston and Jefferson Streets


REFINEMENT CONCEPT - 3BSplit Diamond Interchange with Depressed Open Connector Roads

• RR Crossing Grade Separations maintained at Johnston and 2nd/3rd Streets

• Existing Jefferson Street RR Crossing Grade Separation converted to at-grade with Jefferson Street spanning over connecting roads in trench


Elevated Freeway

Split Diamond Interchange with Connector Roads Connector Road in Open Trench

Key Features • Change Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) changed to function as a

split diamond interchange with connecting road system between half-diamonds: – Johnston/Louisiana will be half-diamond to/from the south – 2nd/3rd Streets will be half-diamond to/from the north

• Connecting roads between interchanges are depressed, in tunnel section• Freeway maintained on structure between Johnston and Jefferson Streets


REFINEMENT CONCEPT - 3CSplit Diamond Interchange with Depressed Closed Connector Roads

• RR Crossing Grade Separations maintained at Johnston and 2nd/3rd Streets

• Existing Jefferson Street RR Crossing Grade Separation converted to at-grade with Jefferson Street spanning over connecting roads in trench


Split Diamond Interchange with Connector Roads Connector Road in Tunnel

Elevated Freeway

Key Features • Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• 2nd and 3rd Streets split and maintained as part of Downtown Grid Street System• Evangeline Thruway remains connected to overall frontage road system with ramp pairs to I-49

Lafayette Connector: – One-way couplet arterials maintained between ramp pairs – Overall one-way couplet arterials, Johnston Street, 2nd Street and 3rd Street, developed as “Grand

Boulevard” concept with significant landscape and urban design improvements – Intersection treatments enhanced between Evangeline Thruway and Johnston, 2nd and 3rd

Streets (e.g., roundabouts) to create “gateway” entries to Downtown – Potential associated land acquisition program established to create redevelopment area between

and adjacent to one-way couplet arterials• Freeway maintained on structure between Johnston and Jefferson Streets• RR Crossing Grade Separations maintained at Johnston, Jefferson, and 2nd/3rd Streets


Landscaped Arterial Parkway Ramp Pairs Multi-lane Roundabout

REFINEMENT CONCEPT - 4AEvangeline Thruway Connectivity System (with additional RR grade separations)


Lafayette Connector: – One-way couplet arterials maintained between ramp pairs – Overall one-way couplet arterials, Johnston Street, 2nd Street and 3rd Street, developed as “Grand

Boulevard” concept with significant landscape and urban design improvements – Intersection treatments enhanced between Evangeline Thruway and Johnston, 2nd and 3rd Street

(e.g., roundabouts) to create “gateway” entries to Downtown – Potential associated land acquisition program established to create redevelopment area between

and adjacent to one-way couplet arterials• Freeway maintained on structure between Johnston and Jefferson Streets• RR Crossing Grade Separation maintained at Jefferson Street

REFINEMENT CONCEPT - 4BEvangeline Thruway Connectivity System (without additional RR grade separations)


Landscaped Arterial Parkway Ramp Pairs Multi-lane Roundabout


Lafayette Connector: – Paired two-way arterial connectivity system (4 lanes each) developed between ramp pairs – Overall Evangeline Thruway, Johnston Street, 2nd Street and 3rd Street, developed as “Grand



and adjacent to paired arterials• Freeway maintained on structure between Johnston and Jefferson Streets• RR Crossing Grade Separation maintained at Jefferson Street

REFINEMENT CONCEPT - 4CEvangeline Thruway Paired Two-Way Connectivity System (without additional RR grade separations)


Two-Way Urban Arterial Ramp Pairs Urban Roundabout

Key Features • Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• 2nd and 3rd Streets split and maintained as part of Downtown Grid Street System• Existing SB Evangeline Thruway becomes a two-way major arterial (4 or 6 lanes) connected to the

frontage road/ramp pair system from I-49• Existing SB Evangeline Thruway is developed as an “Urban Parkway” with median, and extensive

landscape and urban design improvements• Existing NB Evangeline Thruway is rebuilt as local street and is re-integrated into neighborhood grid

street system• Intersection treatments enhanced between Evangeline Parkway and Johnston, 2nd and 3rd Streets

(e.g., roundabouts) to create “gateway” entries to Downtown• Freeway maintained on structure between Johnston and Jefferson Streets• RR Crossing Grade Separation maintained at Jefferson Street

REFINEMENT CONCEPT - 4DEvangeline Parkway Connectivity System


Two-Way Urban Arterial Urban RoundaboutRamp Pairs


Lafayette Connector: – Paired two-way arterial connectivity system (4 lanes each) developed between ramp pairs – Overall Evangeline Thruway, Johnston Street, 2nd Street and 3rd Street, developed as “Grand



and adjacent to paired arterials• Freeway maintained on structure between Johnston and Jefferson Streets• RR Crossing Grade Separations at Johnston and Jefferson Streets

REFINEMENT CONCEPT - 4EEvangeline Thruway Paired Two-Way Connectivity System (with additional RR grade separation)


Two-Way Urban Arterial Ramp Pairs Urban Roundabout

Key Features • Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• 2nd and 3rd Streets split and maintained as part of Downtown Grid Street System• Existing SB Evangeline Thruway becomes a two-way major arterial (4 or 6 lanes) connected to the

frontage road/ramp pair system from I-49• Existing SB Evangeline Thruway is developed as an “Urban Parkway” with median, and extensive

landscape and urban design improvements• Existing NB Evangeline Thruway is rebuilt as local street and is re-integrated into neighborhood grid

street system• Intersection treatments enhanced between Evangeline Parkway and Johnston, 2nd and 3rd Streets

(e.g., roundabouts) to create “gateway” entries to Downtown• Freeway maintained on structure between Johnston and Jefferson Streets• RR Crossing Grade Separations at Johnston and Jefferson Streets


Two-Way Urban Arterial Urban RoundaboutRamp Pairs

REFINEMENT CONCEPT - 4FEvangeline Parkway Connectivity System (with additional RR grade separation)

Key Features • 2nd/3rd Street Single Point Urban Interchange (SPUI) removed • Johnston Street Single Point Urban Interchange (SPUI) changed to Tight Urban Diamond Interchange

(TUDI)• 2nd and 3rd Streets split and maintained as part of Downtown Grid Street System• Evangeline Thruway returned to local street system, and parallel frontage roads developed throughout

Downtown area along I-49 Connector• Intersection treatments enhanced between frontage roads and Johnston, 2nd and 3rd Street (e.g.,

roundabouts) to create “gateway” entries to Downtown• RR Crossing Grade Separations maintained at Johnston and Jefferson

Streets

REFINEMENT CONCEPT - 5AEvangeline Corridor Local Street System


Elevated Freeway Structure with Continuous Frontage Road

Tight Urban Diamond Interchange (TUDI)

Urban Roundabout

Key Features • I-49 Mainline semi-depressed (approx. 10 ft. below existing Evangeline Thruway) from south of

Pinhook Road to Hobson Street• Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• Jefferson Street RR Crossing Grade Separation removed• Roadway overpasses provided at Pinhook Road, Taft Street, Johnston Street, 6th Street, Jefferson Street,

2nd Street, 3rd Street, Simcoe Street and Mudd Avenue for cross street connectivity• Roadway overpasses at Johnston, 6th, and Jefferson Streets are also elevated over railroad. • Mudd Avenue elevated on structure over Semi-Depressed I-49 Mainline and Frontage Roads• Evangeline Thruway (existing at-grade and new elevated segments) remains connected to overall

frontage road system with ramp pairs to I-49 Lafayette Connector• Cypress Street depressed at 6th and Jefferson Streets

REFINEMENT CONCEPT - 6A (First Draft)Semi-Depressed I-49 Lafayette Connector Mainline


Depressed Freeway Mainline Ramp Pairs Multi-lane Roundabout


Pinhook Road to Hobson Street• Semi-depressed mainline covered from north of Taft Street to Simcoe Street (to create a tunnel like

appearance) to provide opportunity for other uses above the I-49 mainline• Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• Jefferson Street RR Crossing Grade Separation removed• Roadway overpasses provided at Pinhook Road, Taft Street, Johnston Street, 6th Street, Jefferson Street,

2nd Street, 3rd Street, Simcoe Street and Mudd Avenue for cross street connectivity• Roadway overpasses at Johnston, 6th, and Jefferson Streets are also elevated over railroad. • Mudd Avenue elevated on structure over Semi-Depressed I-49 Mainline and Frontage Roads• Evangeline Thruway (existing at-grade and new elevated segments) remains connected to overall

frontage road system with ramp pairs to I-49 Lafayette Connector• Cypress Street depressed at 6th and Jefferson Streets

REFINEMENT CONCEPT - 6B (First Draft)Covered Semi-Depressed I-49 Lafayette Connector Mainline


Covered Freeway Mainline Example Cross-Section

Covered Freewaywith Pedestrian

Walkways, Plazas,Bikeways

Earth Berm Earth Berm



appearance) to provide opportunity for other uses above the I-49 mainline• Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• Jefferson Street RR Crossing Grade Separation and connectivity eliminated• Johnston Street/Louisiana Avenue relocated between Cypress Street and Magnolia Street• Roadway overpasses provided at Pinhook Road, Taft Street, Johnston Street, 2nd Street, 3rd Street, and

Simcoe Street for cross street connectivity• Roadway overpass at Johnston Street also elevated over railroad. • Evangeline Thruway (existing at-grade and new elevated segments) remains connected to overall

frontage road system with ramp pairs to I-49 Lafayette Connector South of Taft Street and at Willow Street Interchange

• Mudd Avenue connects to Northbound and Southbound Frontage Roads, but discontinued across I-49

REFINEMENT CONCEPT - 6C (First Draft)Covered Semi-Depressed I-49 Lafayette Connector Mainline with Relocated Johnston Street








appearance) to provide opportunity for other uses above the I-49 mainline• Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• Jefferson Street RR Crossing Grade Separation removed• Roadway overpasses provided at Pinhook Road, Taft Street, Johnston Street, 6th Street, Jefferson Street,

2nd Street, 3rd Street, Simcoe Street and Mudd Avenue for cross street connectivity• Roadway overpasses at Johnston, 6th, and Jefferson Streets are also elevated over railroad • Mudd Avenue connects to Northbound and Southbound Frontage Roads, but discontinued across I-49• Evangeline Thruway (existing at-grade and new elevated segments) remains connected to overall

frontage road system with ramp pairs to I-49 Lafayette Connector• Cypress Street depressed at Jefferson Street

REFINEMENT CONCEPT - 6D (First Draft)Covered Semi-Depressed I-49 Lafayette Connector Mainline






Key Features • I-49 Mainline re-aligned and semi-depressed (approx. 10 ft. below existing Evangeline Thruway) by

shifting to the east from south of Pinhook Road to Hobson Street• Railroad re-aligned and semi-depressed (approx. 10 ft.) by shifting to the east• Semi-depressed I-49 mainline and railroad covered from north of Taft Street to Simcoe Street (to create

a tunnel like appearance) to provide opportunity for other uses above the I-49 mainline• Johnston and 2nd/3rd Street Single Point Urban Interchanges (SPUI) removed• Jefferson Street RR Crossing Grade Separation removed• Amtrak Terminal at Rosa Parks Transportation Center extended to new railroad alignment• Roadway overpasses provided at Pinhook Road, Johnston Street, Jefferson Street, 2nd Street, 3rd Street,

and Mudd Avenue for cross street connectivity• Roadway overpasses at Johnston, and Jefferson Streets are also elevated over railroad• Mudd Avenue elevated on structure over Semi-Depressed I-49 Mainline and Frontage Roads• Southbound Evangeline Thruway elevated to match slope of cover• Evangeline Thruway (existing at-grade and new elevated segments) remains connected to overall

frontage road system with ramp pairs to I-49 Lafayette Connector

REFINEMENT CONCEPT - 6E (First Draft)Covered Semi-Depressed I-49 Lafayette Connector Mainline and Railroad


Example Cross-Section: Johnston to 2nd Street




SB Thruway

NB Thruway

KEY DESIGN FEATURESAPPLICABLE TO ALL REFINEMENT CONCEPTS

ELEVATED FREEWAY STRUCTURE

SIGNATURE BRIDGE

USES UNDER FREEWAY STRUCTURE

RAILROAD UNDERPASS

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Documents

19 proposed I-49 refinements