California Department of Transportation

Construction Analysis for Pavement Rehabilitation Strategies
Caltrans "Rapid Rehab" Software

Rapid Road Rehabilitation is a set of applications facilitating the analysis of scheduling, traffic, and costs for highway projects. Developed by Pavia Systems, R3 is a suite of scoping tools based on the research behind CA4PRS, originally developed in 1999 by E.B. Lee from the University of California at Berkeley.

A Decision-Support Tool to Integrate Design, Construction, and Traffic for Highway Projects

Development Background

State transportation agencies are increasingly shifting their focus from constructing new highways to rehabilitating and reconstructing existing facilities. Because highway rehabilitation projects often cause congestion, safety problems, and limited access for road users, agencies face a challenge in finding economical ways to rehabilitate deteriorating roadways in metropolitan areas while keeping the traveling public as safe as possible and minimizing disruptions for local communities and surrounding businesses.

One innovation in the effort to reduce highway construction time and its impact on traffic is software called CA4PRS, Construction Analysis for Pavement Rehabilitation Strategies. CA4PRS is a schedule and traffic analysis tool that helps planners and designers select effective, economical rehabilitation strategies. Funded through an FHWA (Federal Highway Administration) pooled-fund, multistate consortium (California, Minnesota, Texas, and Washington), CA4PRS was developed by the University of California Pavement Research Center (UCPRC) through the UC Berkeley Institute of Transportation Studies. FHWA formally endorsed CA4PRS as a "Priority, Market-Ready Technologies and Innovations" product in 2008 for national wide deployment. Recently, FHWA arranged the CA4PRS group license with the UC Berkeley for all 50 state DOTs, as an extension of their pooled fund program.

The software's scheduling module estimates highway project duration (total number of closures), incorporating alternative strategies for pavement designs, lane-closure tactics, and contractor logistics. CA4PRS's traffic module (using the Highway Capacity Manual demand capacity model) quantifies the impact of construction work zone closures on the traveling public in terms of road user cost and time spent in queue.

The use of CA4PRS is especially beneficial for transportation agencies when it is implemented during the planning and design stages of highway project development in order to balance schedule (construction production), inconvenience (traffic delay), and affordability (agency budget).

CA4PRS compares rehabilitation alternatives as "what-if" scenarios for the analytical criteria and its sub-parameters
(shown above: the CA4PRS analysis framework (left) and what-if scenario parameters (right)).

CA4PRS Benefits

Demonstrations have shown that CA4PRS is user-friendly, easy to learn, and valuable in any project phase. Its greatest value lies in its capability to provide information to the planner/designer to optimally balance pavement design, construction constraints, traffic operations, and agency budget for transportation agencies - especially during the planning and design of rehabilitation projects.

CA4PRS helps agencies, contractors, and consultants prepare strategies (including the PS&E package) for highway projects by:

  • Estimating working days and CPM schedules,
  • Developing construction staging plans,
  • Supplementing traffic management plans, and
  • Outlining incentives and cost (A) + schedule (B) contracts

CA4PRS enhancements in development include analyzing strategies for roadway widening (version 2.5) and bridge/interchange replacement (version 3.0).

Implementation Experience

Since 1999, the capabilities of CA4PRS have been confirmed on several major highway rehabilitation projects in states including California, Washington, and Minnesota. The software was validated on the 2.8-lane-km I-10 Pomona Project, which used fast-setting hydraulic cement concrete and was completed in one 55-hour weekend closure. The software was also used to develop a construction staging plan for the I-710 Long Beach Project, where 26 lane-km of asphalt concrete were reconstructed in a series of eight 55-hour weekend closures-two weekends ahead of schedule.

More recently, CA4PRS was used with traffic simulation models to select the most economical rehabilitation scenario for the I-15 Devore Project (see table on the next page). The 4.5-km concrete reconstruction project, which would have taken 10 months using traditional nighttime closures, was completed over two 9-day periods using one-roadbed continuous closures and around-the-clock construction. Implementing continuous closures rather than repeated nighttime closures in this project resulted in significant savings: $6 million in agency costs and $2 million in road user costs. Alternative strategies enabled by use of CA4PRS led to an accelerated project process dubbed "Rapid Rehab" that was praised by professionals.

Other sponsoring state transportation departments have also used CA4PRS for analyses of corridor rehabilitations. The Washington State DOT used it to analyze reconstruction of Interstate 5 through Seattle. The Minnesota DOT used it to analyze the rehabilitation of interstates 394 and 494 in St. Paul.

CA4PRS software justified implementing the one-roadbed continuous closure scenario, which saved significant agency and user delay costs, on the I-15 Devore Reconstruction Project.

Cost Comparison ($M)
Continuous (24/7)
72-Hour Weekday
55-Hour Weekend
10-Hour Night-time

Nationwide Outreach

Throughout the U.S. there is growing recognition of the capabilities and benefits of CA4PRS. It has been presented at national conferences and workshops hosted by the TRB, AASHTO, and FHWA; and articles about it have been published in professional journals (including ASCE and TRR), transportation magazines such as TR News, FOCUS, and Public Roads, and industry (ACPA and NAPA) newsletters.

To boost nationwide deployment, FHWA recently arranged CA4PRS free group licenses for all 50 states (as mentioned above). With this arrangement all State highway agencies may now have unlimited access to the CA4PRS software and associated technical support at their request and at no cost Basic training in the use of the CA4PRS software will also be available to states at no cost for a limited period of time on a first come first serve basis. FHWA encourages use of CA4PRS for highway rehabilitation projects by conducting workshops and training sessions through the National Highway Institute (NHI). AASHTO also endorses wider use of the software. The AASHTO Technology Implementation Group (TIG) is focusing on CA4PRS for nationwide promotion to its state members, and is in the process of establishing a campaign to market the software in the AASHTOWare product line. As a recent research payoff, CA4PRS won a 2007 Global Road Achievement Award granted by the International Road Federation.


CA4PRS User Interface

CA4PRS User Interface

Microscopic Traffic Simulation

Microscopic Traffic Simulation

Integration with Work-zone Traffic Simulation

CA4PRS yields additional benefits when its results are integrated with various traffic simulation modeling tools in quantifying the impact of work zone lane closures to the whole highway network, including local arterials and neighboring freeways. To experience an example of microscopic traffic simulation (using Paramics software) performed for the I-15 Devore reconstruction project, click the screenshot of the simulation above (right).

A workshop was held in Sacramento on March 20-21, 2007 with the main focus of traffic network simulation models for construction work zone, especially for the development of TMP based on simulations and incorporation with CA4PRS. FHWA sponsored the fund for this workshop to have the presentations from the experts (State DOTs, consultants, and academia) in this area. Topics presented and shared in the workshop include decision making process on network model selection, applying model outputs to an individual highway project (work zones) for TMP, and making policy level decisions about organizational and business practices.

More details about the workshop ("Optimizing Traffic Management Using Modeling Techniques for Major Urban Construction"), including the agenda and individual presentations, are available on the post-workshop website. (Please click here for the link.)

System Requirement

CA4PRS is stand-alone software, so end users only need to install the program itself to use it. The software runs on Microsoft Windows 95/NT4.0/98/2000/XP or higher operating systems and on computer systems with reasonably up-to-date hardware components. CA4PRS employs a multiple-document interface - similar to Microsoft's programs like Excel and Word - which enables users to open, view, and compare multiple projects and analyses simultaneously.

CA4PRS References

Download and Copyright

All 50 state Departments of Transportation (DOTs) including Caltrans have an unlimited free license for the R3-CA4PRS software for their internal use. Site maintenance and training are provided by PAVIA Systems under separated contract.

Contact Information

Caltrans Division of Research, Innovation and System Information

Michael Samadian: Contract Monitor
Phone: (916) 227-6207

For commercial and educational licensing of the software, please contact:
(510) 643-7201
IPIRA- Office of Technology Licensing
University of California, Berkeley
2150 Shattuck Avenue, Suite 510
Berkeley, CA 94704-1347