ASCE Presentation Sam Rayburn Tollway US 75 Interchange

ASCE Presentation Sam Rayburn Tollway/ US 75 Interchange (Segment 4) Presenters: Mark Bouma, P. E. Technical Oversight Leader North Texas Tollway Authority Michael Bauer, P. E. North Texas Operations Manager Jacobs Engineering

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Milestones & 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 3

Segment 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 4

The 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 5

Interchange 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, Mc. Kinney – Tx. DOT & NTTA 6

Schematic 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 7

Approved Tx. DOT Schematic • US 75 – 8 lane divided – Space for future HOV lanes – Depressed below grade through interchange • • SH 121 – 6 lane divided Single lane DC Bridges Long-span steel bridges through interchange Boxed (signalized) frontage connections – Texas U-Turns 8

Approved Tx. DOT Schematic: 9

Proposed Schematic: • US 75 – 8 lane divided – Space for future HOV lanes – Remains at or near current grade • • • SH 121 – 6 lane divided Two lane DC Bridges All bridges pre-stressed concrete Loop ramp frontage connections Additional on/off ramps 10

Proposed Schematic: 11

Interchange 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 12

Interchange 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 13

Interchange 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 14

Interchange Enhancements: Get In, Get Out, Stay Out • Proposed Configuration Improves Constructability – – – Eliminate one level of the interchange US 75 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 15

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 Project. Wise used for coordination and organization of project files 16

Tools & Automation • Best practices developed and applied – Design Cross Sections – 3 D 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 17

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 18

Construction • NTTA Construction Manager – KBR • Contractor - W. W. WEBBER – Bid 65% plans, issued 100% PS&E after award – Low Bid $219. 8 M – 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 19

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 20

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Construction by the Numbers • Tallest Point – 80’ (~6 stories) • Concrete used – ~5 M ft 3; enough for a sidewalk from Dallas to New Orleans (450 mi) • Longest Continuous Bridge – 4, 800 ft; length of ~16 football fields • Concrete barriers and rail – ~36 mi; enough to stretch from Mc. Kinney to DFW International Airport • Concrete Beams – 24 mi worth; laid end-to-end would stretch from Allen to downtown Dallas • Soil used as fill – ~1. 3 M yd 3; amount which would fill 130, 000 dump trucks (lined end-to-end would stretch 620 mi from Dallas to St. Louis) • Sod placed – 75 football fields worth or 1 -18 hole golf course 29

THE END QUESTIONS 30