Work Zone Mobility and Safety Program

CA4PRS and Accelerated Road Work

slide 1: Construction Analysis for Pavement Rehabilitation Strategies

CA4PRS, 'Rapid Rehab' Software for Highway Projects.

Accelerated Road Work for Work Zone Safety & Mobility
Peer Exchange Workshop
June 5-6, 2012

E.B. Lee
Institute of Transportation Studies
Univ. of California at Berkeley

Chang Mo Kim
University of California at Davis

slide notes:

CA4PRS is a software tool that helps agencies to analyze pavement rehabilitation strategies from the many relevant aspects associated with the work:

  • Traffic
  • Pavement selection
  • Contractor access
  • Production rates and resources
  • Agency costs

The tool allows the implementation of an integrated analysis process, with all stakeholders (each seeking to optimize one of the competing objectives) working together.

slide 2: Transportation Trends (1970-2010)

Stylizing chart shows that since 1970, the population is up 32%, number of drivers is up 63%, number of vehicles is up 90%, travel miles are up 132%, ton miles are up 580%, and highways are only up 6%.

slide notes:

This slide shows some trends in the field of transportation that I'm sure all of us are familiar with. This serves as background for the reason tools like CA4PRS are needed.

slide 3: CA4PRS History

  • CA4PRS Software Development
    • Pooled-fund (CA, FL, MN, TX, WA): UC Berkeley 2003
    • Help DOT agencies develop more economical highway construction and TMP strategies
  • FHWA Outreach
    • 2009 Market-ready Innovation and Technology Product
    • Arranged Free-group License for State DOTs
    • Training: 1,200 Eng (20 DOTs), 12 univ., Online course
  • AASHTO Promotion
    • CAST: WZ Traffic Tools: 2007-2009

slide notes:

CAST (Construction Analysis Software Tool). CA4PRS was promoted as part of an AASHTO TIG (Technology Implementation Group) for CAST.

slide 4: CA4PRS Analysis Process

Diagram of teh CA4PRS decision support model.

slide notes:

This is an integrated project development work process instead of the traditional sequential work process. Traditional process is: plan, traffic windows, design, construction in order. When a problem is found the project gets sent back upstream. In the integrated multi-discipline process have the planners, traffic engineers, designers, and construction and maintenance engineers all sit together, and work together using the tools to try different scenarios. This results in the « what-ifs » being analyzed ONE time. Minimizes rework, speeds project delivery.

Decisions are made based on calculation of Traffic Delay, Agency Cost and User Delay Cost.

Traffic simulation software allows simultaneous and QUANTITATIVE analysis of construction schedule and traffic delay.

Can use traffic delay calculations to calculate appropriate schedule incentives and disincentives for contractors, so the agency isn't paying too much.

slide 5: CA4PRS Comparison Alternatives

  • Pavement Design Alternatives
    • Maintenance & Rehabilitation Strategies
      • Rigid: JPCP, CRCP, Precast
      • Flexible: Overlay, Milling-filling AC, Full-depth AC
    • Variation: Cross-section, Mix, Base type
  • Work-zone Traffic Alternatives
    • Closure timing (Night, Day, Weekend, Continuous)
    • Optimized Lane Closure Hours & Numbers
    • WZ Demand Sensitivity & Capacity Sensitivity
  • Contractor's Logistics Alternatives
    • Site access and Construction sequence
    • Constructability (demo/mix): Resource optimization
  • Competing Objectives: Integration & Collaboration

slide notes:


slide 6: CA4PRS Estimate – Agency (Project) Cost

  • Pavement Cost: Itemized unit-price and quantity
    • Materials (PCC, HMA, RAC, Pre-cast), Base, Subbase
    • Item unit-price from bid-database
  • Non-pavement Cost: % of construction cost
    • Earth work cost; Drainage cost
    • Specialty items(Retaining/Barrier), Stormwater (SWPPP)
  • Traffic Costs
    • TMP (COZEEP, I/D) and Traffic-handling, Outreach
  • Indirect Cost: % of construction cost
    • Minor Items, Mobilization, Supplemental, Contingency
    • Support: Agency (Plan, Design, Traffic, Construction)
  • Other Optional Costs
    • Structures and ROW

→ Total Project Cost

slide notes:

Since audience is traffic people, don't need to spend a lot of time on this slide.

slide 7: CA4PRS Implementation in the Project Life Cycle Process

  • Planning Stage (PSR/PA&ED): Scope and Priority
    • VE Analysis and Life-cycle Cost Analysis
  • Design Stage: PS&E & TMP packages
    • Working-days (CPM); Construction staging plans
    • TMP Report and Lane closure chart
    • Contract Type Selection: A (cost)+B(schedule); I/D
  • Construction Stage
    • Validate contractor's work-plans and CCOs
  • Upcoming Enhancement Modules
    • V3.0 Roadway Widening Module
    • V4.0 Bridge Replacement Module
    • V5.0 LCCA Interaction Module

slide notes:

Roadway widening will be useful for the many HOV projects coming up in CA. V 3.0 by end of this year. V 4.0 in next 1-2 years. V 5.0 in about 3 years.

slide 8: CA4PRS Nationwide Implementation Map

Map depicting CA4PRS nationwide implementation.

slide notes:

Four states participated in FHWA pool fund study to develop the tool. CA took the lead and used the CA4PRS in few locations.

slide 9: CA4PRS Implementation Projects List (as of Feb 2011)

List of 15 CADOT and 7 other state DOT projects where CA4PRS has been used.

slide notes:

  • CA4PRS has been used on the projects shown here.
  • WA and MN DOTs have used CA4PRS for analyses for two corridor rehabilitations.
  • The whole integrated process was used by Caltrans District 8 on I-15 Devore, including for public outreach efforts

slide 10: Concrete Pavement Cross-sections

a) Cross section of pavement using milling filling AC.  b) Cross section of concrete slab replacement with SG below 12 inches of AB below 4 inches of CTB below 8 inches of concrete.   or c) Cross section of concrete slab and base reconstruction with SG below 6 inches of AB below 6 inches of base below 12 inches of concrete.

slide notes:

These are samples. Custom sections are possible, as well as things like precast pavement.

slide 11: Closure ↔ Access ↔ Production
Full Closure for Concurrent Method

Representative diagram of traffic roadbed with lanes 1 and 2 carrying southbound traffic and lanes 3 and 4 carrying northbound traffic. Shoulder 1 is to the right of drivers traveling southbound, and shoulder 2 is to the right of drivers traveling northbound.   Representative diagram of construction roadbed with shoulder 1 and lanes 1 and 2 being accessible and lanes 3 and 4 and shoulder 2 being closed for reconstruction.

Chart shows that from the point of mobilization, progress is made rapidly in demolition, base paving, and PCC paving to the point of demobilization from hours 60 to 72.

Long Closure
Better Access
Faster Schedule
Higher Delay/Closure

slide notes:

Explain each diagram.
Production per closure is much higher.

slide 12: Closure ↔ Access ↔ Production
Partial Closure for Sequential Method

Representative diagram of traffic roadbed with lanes 1, 2, 3 and 4 carrying southbound traffic. Shoulder 1 is to the right of drivers traveling southbound, and shoulder 2 is to the left of drivers traveling northbound.   Representative diagram of construction roadbed with shoulder 1 and lanes 1 and 2 being used for northbound traffic, lane 3 being used for access, and lane 4 and shoulder 2 being closed for reconstruction.

Chart shows that from the point of mobilization, progress in demolition, base paving, and PCC paving is slower than for complete closing with the concurrent method.

Short Closure
Limited Access
Slower Schedule
Less Delay/Closure

slide notes:


slide 13: CA4PRS WZ Traffic Module Inputs & Outputs (HCM Model)

  • Basic Input Data
    • Closure schedule.
    • 24-hour traffic volumes.
    • User's Time values (vehicle cost)
  • WZ Impact Analysis Outputs
    • Max queue length and max delay per closure
    • Total Road User Cost
    • WZ Capacity (Sensitivity) and Demand Management
  • Road user cost (RUC) Components
    • Delay cost; Vehicle operation costs: Detour cost
  • WZ Analysis Application
    • Evaluate TMP (Lane Closure) Strategies
    • Contract: Incentives/Disincentive & A+B

slide notes:

Federal Regulation Amendment 23 CFR 630.1006: "Each State shall implement a policy for the systematic consideration and management of work zone impacts on all Federal-aid highway projects. This policy shall address work zone impacts throughout the various stages of the project development and implementation process. This policy may take the form of processes, procedures, and/or guidance, and may vary based on the characteristics and expected work zone impacts of individual projects or classes of projects. The States should institute this policy using a multi-disciplinary team and in partnership with the FHWA. The States are encouraged to implement this policy for non-Federal-aid projects as well."

Vehicle operation costs are from FHWA numbers. WZ impact analysis uses the Demand-Capacity Model (HCM Ch. 29).

CA4PRS is a tool that helps to address the requirements of this regulation.

slide 14:

Screenshot of the work zone analysis tab in the CA4PRS program.

slide notes:

slide 15:

Screenshot of the work zone analysis tab in the CA4PRS program with the traffic data group dropdown activated.

slide notes:


slide 16: Importing Traffic Demand

Screenshot of the traffic hourly demand screen in the CA4PRS program.

slide notes:


slide 17:

Screenshot of the California Performance Measurement System showing a road map with many PeMS stations marked along the roadways.

slide notes:

PeMS – Performance Measurement System
Green dot is one PeMS station.

slide 18:

Screenshot of a California Performance Measurement System screen next to an Excel spreadsheet.

slide notes:

Note some of the configuration parameters. CA4PRS can import this format.

slide 19: Lane Closure Charts

Screenshot of a CA4PRS lane closure chart.

slide notes:


slide 20: Work Zone Capacity

Screenshot of a CA4PRS work zone capacity adjustment screen.

slide notes:


slide 21: Delay Calculation

Screenshot of a demand capacity model generated by CA4PRS to illustrate work zone delay.

slide notes:


slide 22: Outputs: Summary of Results

Screenshot of the summary tab of a work zone traffic analysis screen generated by CA4PRS.

slide notes:


slide 23: Output: Hourly Traffic Patterns

Screenshot of the hourly graphs tab of a work zone traffic analysis screen generated by CA4PRS.

slide notes:


slide 24: Output: Lane Required

Screenshot of the lanes open tab of a work zone traffic analysis screen generated by CA4PRS.

slide notes:


slide 25: Example – Sensitivity Analysis on Demand Management

Scenarios Demand Control Maximum Delay Maximum Queue Daily User Cost Total User Cost
Scenario 1

No show 0 %

Detour 0 %

57 min 3.3 miles $ 71K $ 8.2M
Scenario 2

No show 5 %

Detour 5 %

37 min 2.6 miles $ 41K $ 4.7M
Scenario 3

No show 10 %

Detour 10 %

24 min 1.9 miles $ 19K $ 2.2M

Scenario 1 has the highest user cost and creates the greatest delay. Scenario two creates a more moderate amount of delay but still entails a sizeable user cost. Scenario three offers the best alternative in terms of both delay and user cost.

slide notes:


slide 26:

For the I-15 Devore PCC Reconstruction Project in 2005, 10 lane-miles of PCC pavement were rebuilt over two 9-day closures (non-stop construction), which saved $8 million in agency cost. This would have taken 10 months of nighttime closures to complete.

slide notes:

I-15 notes:

ADTs: 111K (M-Th); 127K (F); 115K (Sat); 110 (Sun)

3 centerline miles. Major corridor connecting LA to the mid-west. Also many commuters between high desert and the basin. Major traffic to Las Vegas on Friday afternoon and returning on Sunday afternoon made 55 hour weekend closures not the optimal solution. Nearest available detour adds 3 hours. Replacement of outer lane with thicker slab, doweled, new asphalt base. Inner truck lane was originally to also be replaced, but cost was too high. Instead had slab replacements.

Traffic handling: used Moveable Concrete Barrier (MCB) to move all traffic onto one side of the freeway, freeing the other side for construction.

Schedule: Two continuous 9 day closures.

slide 27: I-15 Devore WZ Capacity: Full-closure Dynamic Lane Configuration Using QCMB

Aerial photo of a zipper truck implementing dynamic lane change.

slide notes:

In our LRC input menu, can demonstrate the advantage of this technology.

TMP cost on this project was around $1M (double-check).

Using this on Devore resulted lowered the RUC from $6M (over 1 hr) to less than $1M (less than 20 min). So worth the cost of the equipment.

slide 28: I-15 Devore Pre-construction Analysis CA4PRS Schedule-Traffic-Cost Comparison

Construction Scenario Construction Schedule WZ Traffic Delay Cost
Total Closures Closure Hours Max. Delay (Min) Delay (RUC) Cost ($M) Agency Cost ($M) Total Cost ($M)
One Roadbed Continuous (24/7) 2 400 80 5.0 25.0 30.0
72-Hour Weekday Non-stop 8 576 50 8.0 26.0 34.0
55-Hour Weekend Extended 16 880 80 14.0 27.0 41.0
9-Hour Nighttime Closures 230 2,100 50 7.0 31.0 38.0
8-Hour Nighttime Closures 300 2,400 20 3.0 33.0 36.0
7-Hour Nighttime Closures 410 2,900 10 1.0 35.0 36.0

slide notes:

Agency cost savings are for construction cost and traffic handling ONLY. They do NOT include any calculation of Caltrans support costs.

Costs shown are for: JdH: Advantage of accel. Construction is not just cost savings in RUC. There is also savings in agency cost due to the type of pavements that can be used. Pavement design life is also an issue, especially RSC and FSHCC

Project length was 3 miles, 1 truck lane reconstructed in each direction, 1 truck lane with slab replacements

Alternatives scenarios considered by integrated team

CA4PRS used to calculate schedules

Demand/Capacity; FREQ and Paramics traffic analyses to calculate road user delay, calculate delay costs

Paramics simulations and CA4PRS results used for public outreach meetings

Costs for each alternative shown

Project selected was first one: 1 Roadbed Continuous closure (2 closures, each 9 days)

This information was used for the public hearing and conveyed what Caltrans was trying to do (save $ and minimize total impact on public).

slide 29: I-15 Devore Web Surveys – Public Perception

In response to the survey question 'Do you support 72 hour (3 weekday) Weekday closures?' 64 percent said no, nighttime or weekend work only; 14 percent said no, cancel the project; 7 percent supported continuous closures, 4 percent supported adding a lane, and 11 percent had other negative response.
Do you support 72-h (3-weekday)
Weekday closures?
After Construction
When surveyed with the question 'Do you support future 'Rapid-Rehab' projects?' 70 percent of respondents said 'yes,' and only 30 percent said 'no.'
Do you support future "Rapid Rehab" projects?

slide notes:


slide 30: CA4PRS on Caltrans Web

Screenshot of CA DOT web page containing the Construction Analysis for Pavement Rehabilitation Strategies, the Caltrans 'Rapid Rehab' Software.

slide notes:

Will mention this info and contact info again at the end.

slide 31: CA4PRS Download and Installation

Screenshot of CA DOT web page containing the download and installation information for the Construction Analysis for Pavement Rehabilitation Strategies 'Rapid Rehab' Software.

slide notes:


slide 32: More Information?


Dr. E.B. Lee: UC Berkeley-ITS (510) 665-3637;

Dr. Chang Mo Kim: UC Davis (530) 752-4886;

Ken Jacoby: FHWA Asset Management (202) 366-6503;

Siva Nadarajah: FHWA Turner-Fairbank Highway Research Center (202) 493-3147;

slide notes:


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