Kunhee (KC) Choi, Ph.D.Associate Head of the Construction Science Department

Associate Research Scientist of TTI

2007.06 TxDOT Short Course

Construction IOctober 15, 2019

Determining the Most Economical B Values of A+B Bidding: Worst and Best Use Cases

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I. Backgrounds

II. Worst Use Case

III. Seven-Step Procedure

IV. Best Use Case

V. Discussions

Agenda

Paradigm Shift

Highway Construction Paradigm Shifts to 3R

New Paradigm in Highway Construction

From building new highways to 3R

30% of the Rehab projects in urban corridors

Created an urgent dual challenge

Increased pressure to complete project early

Ever-Increased Pressure for Early Project Completion

Rehab71%

Bridge Renewal

6%

Widening18%

New Highway

3%

New Bridge

1%

Other1%

Rehab71%

Time-Cost Tradeoff CurveExtra acceleration requires additional cost.

Time-Cost Tradeoff Curve

blocker

Innovative strategies improve cost-time performance!

OrdinarySchedule

AcceleratedSchedule

EconomicSchedule

Time-Cost Performance versus Alternative Contracting MethodsA quantitative study presented a case in which A+B projects revealed a critical performance issue!!

On-time &On-budget

Time-Cost Performance versus Alternative Contracting Methods

A+B

I/D

NEB

Lump Sum

DBB

A quantitative study presented a case in which A+B projects revealed a critical performance issue!!

Cost-plus-Time Bidding with I/D

Alternative Contracting Methods

Growing need of early project completion

Design-Build

Cost-plus-Time (aka, A+B)

Incentive/Disincentive (I/D)

A+B combined with I/D provisions

On April 29, 2007, a fully loaded gasoline tanker truck turned over.

The route is a major commuter route in the San Francisco Bay Area.

Caltrans estimated 50 days with an incentive bonus of $200,000 per each day the project was completed, with a cap of $5 million.

The winning bid was for $876,075, about one-third of the total project cost.

In the end, the contractor completed it in 25 days, and thus received the entire $5-million incentive.

Later, it was discovered that the realistic project duration and cost would have been 25 days and $1.75 million dollars.

Importance of Contract Time: I-580 Bay Area Project with I/D

I-580 Bridge Repair Project

Importance of Contract Time: I-580 Bay Area Project with I/D

“There is no justification for this project to cost more than 1.8 million

dollars, but the Department spent 5.88

million dollars, three times higher than the

realistic cost of the project.”I-580 Bridge Repair Project

I. Backgrounds

II. Worst Use Case

III. Seven-Step Procedure

IV. Best Use Case

V. Discussions

Agenda

Production Rates for Concrete Weekend Closures: Normal vs. Accelerated

Production Rates for Concrete Weekend Closures: Normal vs. AcceleratedConcrete

Scope

Weekend Closures Normal vs. Accelerated

Example: Concrete, 10 lane-mile, Long-life, Weekend

Production Rates for Concrete Weekend Closures: Normal vs. Accelerated

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Weekday

Nighttime

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Weekday

Nighttime

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Weekday

Nighttime

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Weekday

Nighttime

No Public Events

No Right-of-Way Issues

No Utility Conflicts

No Adjacent Business and Community Concern

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

IH-20 Dallas6.128mi x 3 lanes x 2 directionsFull-depth 13” CPCD55,257 AADT with 27% truckA+B+I/D with $4,000 daily I/D270 Working Days

Weekday

Nighttime

Weekday Closure is much more favorable than Nighttime in that:

It is 77% faster and 68% saving in reduced road user delay costs.

It yields much higher production rate.

The scope of the project can be accomplished 60 days earlier: 210 vs 270.

Recommendations

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

RecommendationsIncentive/Disincentive (I/D):

The estimated 270 working days by the agency appear slightly overestimated,

which can result in a $240,000 free bonus to the GC without any additional

commitment.

Agency’s estimated daily I/D amount of $4,000 is reasonable, based on the

computed daily RUC of $8,766.

Schedule/Cost/Traffic Integrated Analysis

Best Practice of CTD: TxDOT IH-20 Phase I Project

TxDOT IH-20 Phase I Project: Initial Plan Amended

THANK YOU

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