Presenters:

Mark Bouma, P.E. Michael Bauer, P.E.Technical Oversight Leader North Texas Operations ManagerNorth Texas Tollway Authority Jacobs Engineering

ASCE PresentationSam Rayburn Tollway/US 75 Interchange (Segment 4)

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Milestones & ScheduleMilestones & Schedule

• Approved Schematic – June 2005

• Approved for Tollway Facility in May 2007

• NTTA awarded development rights in 2007

• NTTA awards design contract in 2007:– Segment 4 in October

• Open the Corridor by Jan. 1, 2011

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Segment 4 Schedule ChallengesSegment 4 Schedule Challenges

• 38 months to open the Corridor– Largest single NTTA construction contract at the time

• Approved schematic– Expensive and presented construction challenges– Different functional goals than for a toll facility

• For success, set goal to let contract by Oct. 2008– 3 months to address schematic– 9 months for complete PS&E– 26 months to open, 31 to complete construction

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The TEAMThe TEAM

• Corridor Management Team– Corridor Manager – HDR– Design Manager - Halff Assoc. – NTTA Project Delivery Dept. – HNTB

• Schematic and PS&E Team– Jacobs Engineering - Prime– Bridgefarmer & Assoc.– ARS, IEA, STL

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Interchange Reconfiguration EffortInterchange Reconfiguration Effort

• Identified Alternative that:– Cost Less– Easier to construct in required schedule– Better met functional goals of toll facility– Maintained or improved access w/in ROW

• Staring at daunting schedule

• Need State and Local buy-in– Allen, Fairview, Frisco, McKinney– TxDOT & NTTA

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Schematic EvaluationSchematic Evaluation

• Enhance Safety through Design & Constructability

• Improve Mobility and Accommodate Growth– Design capacity for high volume movements– Minimize typical congestion conditions (short weaves,

unbalanced ML/FR usage, etc)– Segregation of local and highway traffic– Facilitate local access by ramp locations

• Reduce Capital and O&M Costs

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Approved TxDOT SchematicApproved TxDOT Schematic

• US75 – 8 lane divided– Space for future HOV lanes– Depressed below grade through interchange

• SH121 – 6 lane divided• Single lane DC Bridges• Long-span steel bridges through interchange• Boxed (signalized) frontage connections

– Texas U-Turns

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Approved TxDOT Schematic:Approved TxDOT Schematic:

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• US75 – 8 lane divided– Space for future HOV lanes– Remains at or near current grade

• SH121 – 6 lane divided• Two lane DC Bridges• All bridges pre-stressed concrete• Loop ramp frontage connections • Additional on/off ramps

Proposed Schematic:Proposed Schematic:

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Proposed Schematic:Proposed Schematic:

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Interchange Enhancements: SafetyInterchange Enhancements: Safety

• Replaced signalized traffic conflicts with dedicated right turn movements

• Eliminated DC/ML-to-FR conflicts

• Improved merge/weave conditions– Full two lane merge for heaviest DC movements

• Balanced highway and local access movements

• Safety during construction

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Interchange Enhancements: MobilityInterchange Enhancements: Mobility

• Loop ramps for continuous flow FR movements

• Two lane DCs & full ML merge conditions– Improve through-put– Accommodates long-term traffic demand

• Segregates local traffic from highway traffic– Benefits both– Access is maintained or improved

• Mobility during construction

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Interchange Enhancements: Value & CostsInterchange Enhancements: Value & Costs

• Material selection reduced Capital and O&M costs

• Reconfiguration reduced costs– Afforded additional improvements for Safety & Mobility

• Context Sensitive Solution– Toll facility attributes– Improved access increases development value– Aesthetics and configuration provide identity

• Design for future capacity– Reduces future construction impacts– Sustained mobility and access

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Interchange Enhancements:Interchange Enhancements:Get In, Get Out, Stay OutGet In, Get Out, Stay Out

• Proposed Configuration Improves Constructability– Eliminate one level of the interchange– US75 at grade– DC realignment away from interchange core– Natural staging areas– Standardized construction elements for bridges

• Less Commuter impacts during construction– Fewer stages result in fewer traffic adjustments– Use of existing roadways during construction

• Design and Materials promote longevity

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Design Approach

• Project Segmentation– Design Teams for SRT and US 75– Focus initially on geometric tie-down– Teams run concurrent design

• Essentially an Alternative Delivery Style– Weekly Task Force Meetings– Constant client interaction and collaboration

• Bentley ProjectWise used for coordination and organization of project files

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Tools & Automation

• Best practices developed and applied– Design Cross Sections

– 3D Modeling• Highly accurate in pinpointing ponding areas• Provided finished grades for structures

– Drainage• Utilized Geopak Drainage.Tools• Utilized excel Macros to insert drainage callouts on P&P sheets

– Quantity Take-offs• Setup of database for all ‘smart’ design elements• Produced accurate numbers in minutes instead of days

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Review & QA

• Redundant checks employed for critical items– Bridge clearances triple checked

• Spreadsheet calculations• Geopak model cross-check• Inroads model cross-check

• Design Reviews– Peer Review (In-House)– Ongoing Client Reviews– OTS Workshop

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Construction

• NTTA Construction Manager – KBR

• Contractor - W.W. WEBBER– Bid 65% plans, issued 100% PS&E after award– Low Bid $219.8M– NTP October 23, 2008

• Largest NTTA construction contract at the time

• 2.5 years start-to-finish

• Phased opening with the DC’s being top priority

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Construction

• Interactive and Collaborative Construction

• Worked Together to further reduce costs– Adjust North Limits on US 75– Change Pavement Section– Build-out two lanes on SPUR 366– Modified phasing to further support construction

• Additional 5-6% in cost reductions realized

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Photos

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Photos (cont’d)

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Construction by the Numbers

• Tallest Point – 80’ (~6 stories)• Concrete used – ~5M ft3; enough for a sidewalk from

Dallas to New Orleans (450mi)• Longest Continuous Bridge – 4,800 ft; length of ~16

football fields• Concrete barriers and rail – ~36mi; enough to stretch from

McKinney to DFW International Airport• Concrete Beams – 24mi worth; laid end-to-end would

stretch from Allen to downtown Dallas• Soil used as fill – ~1.3M yd3; amount which would fill

130,000 dump trucks (lined end-to-end would stretch 620mi from Dallas to St. Louis)

• Sod placed – 75 football fields worth or 1-18 hole golf course

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THE ENDTHE END

QUESTIONS