Work Zone Mobility and Safety Program

I-15 Precast Pavement Project, Ontario, CA

slide 1: EA 08-472214

Logo for the 'Interstate 15 ONT FIX with Rapid Weekends' project.

Jonathan den Hartog, P.E.

slide notes:

Introduce yourself. $52 million project pavement rehabilitation project. Begun in April 2009. Completion April 2011.

slide 2: Project Overview

  • Purpose & Need: Rehabilitate over 12 lane-miles of deteriorated PCC pavement.
  • Accelerated construction and contracting innovations used:
    • CA4PRS, Dynameq, Extended Weekend Closures, Incentives/Disincentives, Precast Pavement
  • Goal: Minimize disruptions to traffic, without sacrificing quality and pavement life
    • Get in, get out, stay out

slide notes:


slide 3: Project Location

Slide shows map of I-15 corridor and highlights locations of nearby traffic generators, including an airport, NASCAR speedway, mall, amusement park, and commercial areas that generate truck traffic.

slide notes:

Ontario is about 40 miles east of downtown LA

In Addition: Major route for Las Vegas traffic. No break on weekends.

slide 4: Project Location

Map showing intersection of I-15, with 8 lanes and an ADT greater than 200,000, 6 percent of which are trucks, with I-10, which is also an 8-lane facility, and route 60, which also provides 6 to 8 lanes.

slide notes:

Again, no break on weekends

slide 5: Project Features

  • Median Paving & Barrier
  • Bridge Widening
  • AC Shoulder/Ramp Rehab
  • Pavement Rehabilitation
    • 12 ln-mi lane replacement
    • Random slab replacements
    • Includes 12 freeway-to-freeway connectors
    • Precast Pavement (Super-Slab)

Traffic camera photo of I-15 showing light traffic conditions.

slide notes:

Picture is non-rush hour, on a weekday. Saturday would be similar. All days can have traffic jams. Bridge widening was to close the gap between NB and SB bridge decks.

slide 6: Traffic Volumes

I-15 Ontario daily traffic volumes: NB weekdays - 117K ADT. NB Saturdays - 107K ADT. SB Weekdays - 103 ADT. SB Saturdays - 105K ADT.

slide notes:


slide 7: Traffic Impact Mitigation Strategies

  • CA4PRS
  • Dynameq
  • Incentives / Disincentives
  • PCMS usage
  • Media Outreach

Workmen installing precast slabs at night.

slide notes:

PCMS usage needs to be incorporated early, to address any environmental concerns.

slide 8: Construction Sequence

  • Pave median, widen bridges
  • Shift southbound I-15 two lanes toward the CL
  • Rehab pavement weekday and weekend
  • Repeat for northbound I-15

Illustration shows open lanes southbound with partial closure for roadbed reconstruction northbound.

slide notes:

We came up with this strategy as our original plan to manage construction. Based on lessons learned from Devore I. Justified paving the median.

slide 9: Typical Closure

Engineering diagram of road closure plan

slide notes:


slide 10: Rapid Weekeds

  • 5 Major Stages, 25 sub-stages
  • 410 Working Days (~2 yrs)
  • 55-Hour Weekend Closures
    • Beginning late Friday evening
    • Ending early Monday morning
  • Approximately 30 weekends
  • ~8 full roadbed closures

slide notes:

Needed CA4PRS to justify this approach (and determine some of these numbers).

Also, wanted to include incentive to reduce number of weekend closures. Needed to justify this.

slide 11: Traffic/Staging Analysis

  • CA4PRS
    • 2 Phase Study
      • Alternative Analysis And Comparison
      • Detailed Study of Preferred Alternative
    • Performed by consultant sub
  • Construction Traffic Modeling (Dynameq)

slide notes:

The subcontractor was Dr. E.B. Lee

Alternative analysis would be used to determine the # of closures, working days for the project and set an incentive/disincentive (if justified)

slide 12: Alternatives Analysis

Alternative Analysis comparison table.

slide notes:

  • Go over columns. Delay is per closure.
  • 2nd alternative dropped out because of safety concerns.
  • Alternative 1 required bridge widening

slide 13: Alternatives Analysis

Alternatives analysis comparison table with alternatives 3 (contraflow) and 4 (progressive continuous) highlighted is overlain by an illustration depicting the lane assignment scheme for these alternatives. The illustration indicates the northbound lanes would be shut entirely for reconstruction, with northbound traffic diverted into the southbound lanes. A quick change moveable barrier would expand or contract the number of southbound lanes used by northbound traffic depending on demand.

slide notes:

Alternatives 3, 4 would have serious traffic delay impacts, and would be difficult to determine peak dir., but might be tolerable if the duration was short.

slide 14: Alternatives Analysis

Alternatives analysis comparison table with alternative 5 highlighted.

slide notes:

Alternative 5 would take a long time, and still result in a inferior product.

slide 15: Alternatives Analysis

Alternatives analysis comparison table with alternative 6 (CSOL) highlighted is overlain by an illustration depicting the lane assignment scheme for this alternative. The illustration indicates the northbound lanes would be shut entirely for reconstruction, with northbound traffic diverted into the southbound lanes. A quick change moveable barrier would expand or contract the number of southbound lanes used by northbound traffic depending on volume requirements.

slide notes:

Alternative 6 was close in value to the original, but would have higher delays, and was not preferred by maintenance

slide 16: Alternatives Analysis

Alternative Analysis comparison table.

slide notes:


slide 17: Road User Costs/Delay

Scenario Demand Reduction 1,500 vphpl* capacity 1,700 vphpl* capacity
$ (Millions)
$ (Millions)
1 – Original 20% 8 61 20 2 18 2
1 – Original 30% 2 16 3 0 0 0
3 – 55-hour Weekend 30% 51 363 119 34 210 63
3 – 55-hour Weekend 40% 25 179 45 13 81 17
4 – Progressive Continuous 30% 51 363 123 34 210 51
4 – Progressive Continuous 40% 25 179 47 13 81 13
5 – 8-hour Nighttime 5% 8 57 418 - - -
5 – 8-hour Nighttime 10% 3 22 133 - - -
6-1 – CSOL (Weekend) 30% 51 363 69 34 210 36
6-1 – CSOL (Weekend) 40% 25 179 25 13 81 10
6-2 – CSOL (Nighttime) 5% 8 57 120 - - -
6-2 – CSOL (Nighttime) 10% 3 22 38 - - -

* vphpl: vehicle per hour per lane
** RUC: Road User Cost

slide notes:

Note that this was done in a spreadsheet that formed the basis of the module in CA4PRS. It was not a part of CA4PRS when we did our analysis.

On at least one weekend, our vphpl approached 2000.

Actual delay was generally between 10-15 minutes during peak hours.

slide 18: Stage Analysis (Sample)

Stage Station Start Station End No. of Lanes Length (m) Length (lane-km) Rehab Type Total (lane-km) 55-hour Closures Estimate
4B, 4C 836+81 837+81 1 100 0.1 CLR 2.5 2
4B, 4C SB I-15 Conn WB SR-60 SB I-15 Conn WB SR-60 2 773.2 1.546 CLR 2.5 2
4B, 4C SB I-15 Conn EB SR-60 SB I-15 Conn EB SR-60 2 1430.5 0.858 RSR 2.5 2
2A 7+40 11+79 2 439 0.878 CLR 1.28 1
2A Jurupa On-ramp SB I-15 Jurupa On-ramp SB I-15 2 500 0.4 ACR 1.28 1
2B 20+90 22+77 2 187 0.374 CLR 3.01 3
2B 22+77 28+51 1 574 0.574 CLR 3.01 3
2B 28+51 33+03 2 452 0.904 CLR 3.01 3
2B 20+96 28+95 1 799 0.24 RSR 3.01 3
2B WB I-10 CONN SB I-15 WB I-10 CONN SB I-15 1 337.7 0.338 CLR 3.01 3
2B SB I-15 Jurupa Off-ramp SB I-15 Jurupa Off-ramp 2 500 0.4 ACR 3.01 3
2B WB I-10 Conn SB I-15 WB I-10 Conn SB I-15 2 300 0.18 RSR 3.01 3
Note: CLR=Continuous Lane Reconstruction; RSR=Random Slab Replacement; ACR=Asphalt Concrete Rehabilitation

slide notes:

This is a more detailed analysis of the original alternative. Used to determine:

  • Incentive/Disincentive
  • Number of weekends needed (min/max)
  • Working Days
  • Controlling operations

Good check to make sure our staging works, and that the Contractor has sufficient access.

slide 19: Traffic Study (Dynameq)

Screenshots of the maps displayed in the Dynameq mesoscopic model.

slide notes:

Explain mesoscopic.

  • Pros:
    • Less complex than microscopic (less data, faster computation)
    • More info and better accuracy than macroscopic
  • Limitations:
    • Only pre-timed signals
    • Cannot model RR crossings
    • Cannot model single diversion route
    • Equilibrium based

slide 20: Traffic Study (Dynameq)

Closure Delay (min)
Study 1
Delay (min)
Study 2
WB10-SB15 5.5 8.4
EB10-SB15 4.1 7.7
SB15-WB10 4.5 72.6
NB15-E/W10 5.8 58.6
EB10-NB15 5.8 8
Reduce SB 15 3 --
SB15-E/W60 -- 121.4

slide notes:

Don't have modeling expertise in-house. Contracted 2 traffic studies for this project. The second evaluated the first.

Studies looked at 6 closures.

Variables hard to predict: Diversion, detour usage (especially in urban area), effects of economy, user learning

Reduce SB 15 at location studied was not done.

  • WB10-SB15 – Actual, closed EB-SB as well. Detour? Delay < 10 min
  • EB10-SB15 – See previous.
  • SB15-WB10 – Closed SB-EB at the same time, and 4th St onramp. Delay < 10 min. Detour at Jurupa?
  • NB15-E/W10 – Delay < 30 min
  • SB15-E/W60 – Delay < 10 minutes for at least 2 out of 3 of the closures. 1 closure with delays a bit longer, but still under 30 minutes.
  • Note the 15/60 interchange closures.

slide 21: Precast Pavement

  • Pros:
    • Small work windows
    • High quality
    • Long Life
  • Cons:
    • Precise work
    • Expensive
Photos of workers placing precast slabs on the prepared road bed.

slide notes:

  • Highways for Life grant: $5 million
  • Too much pavement (and too risky on pilot) to do whole project in precast. Selected area where it would test well and benefit project.
  • Note differences between this project and I-680 (Tinu's)
  • Production rates: 425 feet (32 panels) per 9-hour closure.
  • CA4PRS can help plan precast pavement work as well.

slide 22: TMP Strategies

  • CA4PRS
  • Dynameq
  • Incentive/Disincentive
  • Project Web Site
  • Brochure/Rack Card
  • Pre-construction meeting with local agencies
  • Regular business meetings
  • For closures:
    • Radio Ads
    • Email
    • Twitter
    • Cancellation disincentive ($25,000)
    • COZEEP

+$150,000 / saved closure (Max $900,000)
-$175,000 / extra closure

slide notes:

  • Brochure left in strategic places. Rack card mailed to local businesses and residents.
  • $150,000 is the average delay damages calculated.
  • Incentive is applied for every closure less than 27 used. Disincentive for every closure over 32.
  • The disincentive includes $25,000 for the public awareness campaign to alert the public about the closure.

slide 23: CA4PRS Validation

Collage of photos depicting workers at a job site.

slide notes:

  • About 18 closures used, so the Contractor got the full incentive.
  • As is often the case, the Contractor changed many things in the construction staging, and was very aggressive in pursuing the incentive.
  • We also experienced lower traffic delays than anticipated, we believe in part due to the economy, and in part due to our public awareness efforts.

slide 24: Inputs: Predicted Vs. Actual

Tab Input Study Actual Unit Default Values
Activity Constraints Mobilization 3 1 hrs 2-3
Activity Constraints Demobilization 2 Varies hrs 4-6
Activity Constraints Concurrent – Demo to Base 15 11 hrs 1-2 (Sequential), 9-10 (Concurrent)
Activity Constraints Concurrent – Base to PCC 8 5 hrs 1-2 (Sequential), 9-10 (Concurrent)
Resource Profile Demo Hauling Truck 22 22 tonne 22
*Resource Profile Demo Trucks per hour per team 10 10 ea 10 for cut & lift, 12 for impact methods
*Resource Profile Demo Packing Efficiency 0.5 0.55 % 0.5 for cut & lift, 0.6 for impact
Resource Profile Demo Number of Teams 2 3 ea 2
*Resource Profile Demo Team Efficiency 0.7 0.7 %
Resource Profile Base Delivery Truck Cap. 10 6 m 10 for bottom dump, 6 for end dump
Resource Profile Base Trucks Per Hour 8 16 ea 10
Resource Profile Base Truck Packing Eff. 100 100 %
*Resource Profile Batch Plant Capacity 90 90 m/hr 100
Resource Profile Concrete Delivery Truck Cap. 6 6 m 7-Jun
Resource Profile Concrete Trucks Per Hour 15 15 ea 15
Resource Profile Concrete Truck Packing Eff. 100 100 %
*Resource Profile Paver Speed 2 2 m/min 2
Resource Profile Number of Pavers 1 1 ea
Schedule Analysis PCC Thickness 290 315 mm
Schedule Analysis Base Thickness 152.4 150 mm
* Unable to verify actual value in field
Orange shaded rows = Difference speeds up actual production
Blue shaded rows = Difference slows down actual production

slide notes:

Explain the table headings

Got this input from talking to construction inspectors, and reviewing the inspector diaries.

Haven't been able to verify every actual input (marked with an asterisk), but we have gotten most of the critical ones.

Define orange vs. blue highlighting

Contractor has really understood that the demolition operation is often the critical operation.

The two slow downs have minimal impact (only minor slow down)

CLICK: Show defaults. Note that at the time of analysis, defaults were not included with the program.

slide 25: Predicted Vs. Actual

  • Random slabs as night work
  • Sometimes paving two lanes wide on connectors
  • Combined stages
  • Concurrent vs. Sequential

Collage of photos depicting workers at a job site.

slide notes:

Demo efficiency was validated by how the contractor performed the Super-Slab work: Fort Miller stated that they have seen very few contractors as efficient as this one on the demo operation.

slide 26: Predicted Vs. Actual (PRELIMINARY)

Stage Plan1 Stage Study1 Stage Description No. of Weekends: Study2 No. of Weekends: Actual2 No. of Weekends:
Revised Inputs3
4B,C 5B,C SB I-15 connectors to E/W SR-60 2 2 Contractor was restricted by width of connector, whichf orced him to pave one lane at a time. Only 2 demo teams used. Thus very similar to study
2B,C 2B,C SB Jurupa offramp, W10-S15 conn, E10-S15 conn 4 2 2 Study had separate closures for 2B, 2C. Contractor chose to combine stages.
2D,E 2D,E SB I-15 connectors to E/W I-10 5 2 2 Contractor may have included more in 2E,F combination, also need to determine how contractor handled 3-lane widths
2E,F 2E,F Fourth St SB ramps 3 1 1 Added 2E work north of S15-E10 connector diverge


1 ‘Plan’ is the stage designation as it is called out on the project plans. ‘Study’ is the stage designation as it is called out in the design study. Differences exist because of changes that occurred between when the study was completed and the project design was finished.
2 ‘Study’ is the number of closures (weekends) estimated to be needed by the design study to complete the work for the stage. ‘Actual’ is the number of closures actually required to complete the work.
3 ‘Revised Inputs’ indicates how many closures were estimated to be needed using the revised inputs for CA4PRS shown in the previous slide.

slide notes:

Read footnotes later.

Used stages that required more than 1 closure.

Explain: This was create merely by running the revised inputs on the same lane-kilometer objective.

  • On the first line, Contractor was restricted by the location to work in a manner very similar to what the study had predicted.
  • Second line, the Contractor combined stages, but the study had them separately.
  • Third line needs more work to determine why the Contractor was able to perform the work in 2 closures. This highlights the challenge of analyzing this type of work. Contractor significantly revised/combined stages to make work more efficient for his crews.

slide 27: CA4PRS Lessons Learned

  • Construction experience is IMPORTANT
  • Design input important for efficiency
  • Breadth of knowledge required
    • Traffic
    • Pavement
    • Construction
    • Estimating
  • Team approach may be best

slide notes:

A team approach may be best, maybe even a dedicated team. D8 would like a team that would also do things like LCCA, estimate verification, etc. Interested to hear suggestions from others with experience with the software.

Study resources (CA4PRS only):

  • Time consuming part is data collection and deciding how the contractor will perform the work.
  • In validation, these things are known already (and hopefully your CA4PRS file is already set up), so validation occurs much more quickly.
  • Pre-Construction Study: ~160 hours
  • Validation of Results: ~40 hours

slide 28: User Survey

Three charts showing users' preferred information sources (Internet, 47%; Email, 17%; radio, 31%; television, 5%; newspaper, 0%), preferred internet source (Caltrans website, 50%; Google, 25%; Other websites, 17%; Twitter, 8%; Facebook, 0%), and the importance they place on the source of information (ranked as follows: public meetings, Twitter updates, newspaper, project brochure, email alert, rack card, and radio ads).

Likert Scale Questions
1 – Strongly disagree ... 5 – Strongly agree

Question Average Std. Dev.
* Prefer extended weekend closures? 3.75 1.32
* Worth it to widen bridges (20% more cost)? 3.64 1.27
* Super-Slab worth it? 4.08 1.14
* Support measures taken to minimize traffic impacts? 3.78 1.08
* Satisfied with pavement rehabilitation? 3.53 1.28

slide notes:

Hard to get respondents.

36 respondents between June 2010 and Feb 2011. However, 32 drove through at least once a week and 22 had been there during a weekend closure.

Survey software: phpESP (open source)

slide 29: Future Directions

  • Continue training on CA4PRS and promote its use on high-impact projects.
  • Statewide Standards group for Precast Pavement Systems (PCPS) to make it easier to use.
  • Multi-disciplinary team to use CA4PRS.

slide notes:

Training must be multi-disciplinary (Ops, Design, Construction)

Most of our design staff and operations staff have been trained.

District Director has been asked by HQ to help in promotion of CA4PRS.

slide 30: Contact Info

Jonathan den Hartog
(909) 383-5998

More info:

slide notes:


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