San Antonio’s I-35 North East Expansion (NEX) Project ...alternatives (eg. Autonomous vehicles, bus on shoulder, etc…) –Project scope includes building elevated lanes and retaining

I-35 NEX November 4, 2019

San Antonio’s I-35 North East Expansion (NEX) Project-Elevated Express LanesPresented by: Daniel Worden

November 4, 2019


Presentation Outline

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6-8

9-20

21-23

3Project Location

Project Need

Project History

Project Challenges

Conclusion

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Disclaimer: The I-35 NEX project is currently in an active design

build (DB) procurement. Topics specific to the procurement will

not be discussed, as well as questions pertaining specifically to

the procurement of the DB contract will not be answered.


I-35 NEX project location & corridor limits

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Project Length: 20 Miles

Construction Limits: Walters St. to

FM 1103

Project Location: Bexar,

Guadalupe, and Comal counties


Project Need

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▪ Population Growth


Project Need

▪ Traffic Growth

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Project History

▪ Planning and Environmental Linkage (PEL) Study completed in 2013

– Developed Need and Purpose

– Studied traffic demand and inadequate capacity

– Recommendation was to add capacity to I-35 and improve I-410 S, I-410

N, and SL 1604 interchanges

– Analyzed ROW impacts of at grade expansion

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Project History

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▪ 2015 Schematic/Environmental effort:

– Proposed adding two tolled elevated managed lanes in each direction of I-35 between main lanes and frontage roads

– Environmentally cleared through an Environmental Assessment

• Public Hearing held in February 2015

• FONSI issued in July 2015

– Due to a statewide focus to move away from tolls, the toll component was eliminated

– Proposed right-of-way identified is currently under acquisition process


Project History

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▪ 2019 EA Re-evaluation:

– Traffic studies indicate the need for 1 additional lane in each direction (HOV)

– HOV lane configuration provides flexibility for future innovative transportation

alternatives (eg. Autonomous vehicles, bus on shoulder, etc…)

– Project scope includes building elevated lanes and retaining a majority of the

existing I-35 capacity and access

– EA Re-evaluation was approved Sept 23rd 2019


Project Challenges

▪ ROW/UTL

– Minimized ROW acquisition, but small strips were necessary in straddle

bent locations

– Total of 80 parcels and 15 acres of ROW acquisition

– ROW acquisition ongoing

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Project Challenges

▪ Phasing:

– Project was broken into 3 phases (Base Central, Base South, Deferred

Work Component North)

• Base Central & Base South are funded

• Deferred Work Component is anticipated to be funded in 2021 UTP, but

is currently unfunded

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AT

&T

Park

way

FM

1103

I-410 N

FM

3009

Base South

• From I-410 North to FM 3009

• Connection to West Loop 1604

Base Central

• From AT&T Parkway to I-410 North

• From FM 3009 to FM 1103

• Connection to East Loop 1604

DWC North

• From AT&T Parkway to I-410 North

• From FM 3009 to FM 1103

• Connection to East Loop 1604


Project Challenges

▪ Interim vs Ultimate Phasing

– Proposed design configuration has minimal throw-away work between

phases

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Project Challenges

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Project Challenges

▪ Structural Approach

– Project consists of 45 linear miles of elevated structure

– Schematic was designed using a traditional Hammerhead Inverted T/TX Girder approach

– Roadway/bridge configuration does not preclude precast/segmental construction methods

– Straddle bents were employed where column eccentricities exceeded hammerhead cap design limits

– Long steel spans are necessary at direct connectors (~350’ max)

– Clearance requirements over cross streets/interchanges

– Provisions in the design build specifications to not preclude future direct connectors at interchanges

– Bent configurations accommodate future cross street expansion

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Project Challenges

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Project Challenges

▪ Roadway/Geometry

– 4’ inside shoulder to reduce project footprint

• Impacts would significantly impact adjacent businesses and residences, as well as introduce safety issues

– Design Exceptions

• Reduced shoulder widths at ramps

• Bents placed in center of I-35

• 11’ auxiliary lane in interim condition

– Constrained horizontal and vertical geometry at interchanges due to existing interchange components

– Shoulder Repairs

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Design Challenges

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Project Challenges

▪ Drainage Approach

– Retrofitting proposed drainage system into existing system

– Available x-sectional space to accommodate new trunk line

– Capture of runoff from elevated structure

• Inlets are proposed at each bent, as well as intermediate inlets in order to meet ponded width requirements

– Conveyance of runoff from elevated structure to new trunk line

• How to pipe runoff from intermediate inlets and incorporate into drainage system

– Hydrologic parameters for future development conditions

– Atlas 14

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Project Challenges

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Project Challenges

▪ Public Involvement

– Stakeholder meetings with local entities

• Met with local municipalities, utility entities, EMS, and major business

owners throughout the corridor

– Meeting With Affected Property Owners

• Conducted one-on-one meetings with property owners that would

require ROW acquisition

– Public Hearing held on August 15th, 2019

• Project received positive public feedback primarily since at grade I-35

and local access would be maintained, and toll component was

removed

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Project Challenges

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Past, Present, & Future

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3D Simulation

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Questions?

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Documents

San Antonio’s I-35 North East Expansion (NEX) Project ...alternatives (eg. Autonomous vehicles, bus on shoulder, etc…) –Project scope includes building elevated lanes and retaining