U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000


Skip to content
Facebook iconYouTube iconTwitter iconFlickr iconLinkedInInstagram

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

 
REPORT
This report is an archived publication and may contain dated technical, contact, and link information
Back to Publication List        
Publication Number:  FHWA-HRT-13-038    Date:  November 2013
Publication Number: FHWA-HRT-13-038
Date: November 2013

 

Reformulated Pavement Remaining Service Life Framework

CHAPTER 3. FUTURE CONSTRUCTION NEEDS ANALYSIS FRAMEWORK

INTRODUCTION

Consistent terminology is necessary to reduce potential confusion over the use of the term RSL. General guidelines on how to formulate future pavement construction needs analysis are provided in this report. The construction needs addressed in this report are associated with correcting pavement surface and structural deficiencies, although many of these concepts could be adapted for construction related to other needs such as capacity and shoulder improvements.

The basic process to determine future pavement construction needs is illustrated in figure 1. Most pavement construction activity planning is based on an annual fiscal time cycle used by the agency. The steps in this figure are cyclical and depend on the time cycle appropriate to the type of pavement asset. The process starts with input data, which are fed into the performance models that predict future changes in the construction trigger models. The outputs from the predictions are used to select the most appropriate construction strategy, which is used to develop construction plans and specifications. The feedback cycle starts with documenting the actual condition observed over time as well as the actual construction activities performed. Monitoring measurements are performed to provide updated inputs for the next planning cycle.

Figure 1. Flowchart. This figure shows a flowchart of the future pavement construction needs process. The flow chart  consists of five boxes that each containing a different element of the process. The first  box, which is located in the upper right corner of the figure, is labeled  "Inputs." An arrow extends from the bottom of the box downward and connects to  the top of the second box labeled "Expectancy Models." An arrow extends from  the bottom of the box downward and connects to the third box labeled "Strategy  Selection." An arrow extends from the left of the third box upward (signifying  a clockwise motion) and connects to the fourth box labeled "Construction." An  arrow extends from the top of the box upward and connects to the final box labeled "Monitoring." An arrow extends from the box and connects back to the first box  labeled "Inputs," completing the flowchart.

Figure 1. Flowchart. Future pavement construction needs process.

While the basic framework illustrated in figure 1 starts with inputs, the input requirements are based on the model used for construction triggers. The framework discussion starts with construction triggers, which are the basis for setting threshold limits and establishing performance models for factors used to select corrective construction strategies (see chapter 4 for additional information).

The following topics must be addressed to develop, implement, maintain, and update a construction needs analysis methodology:

The methods should be tailored to individual agency requirements related to the budgeting process, types of pavements in use, common types of pavement deficiencies requiring correction, construction contract instruments, and other considerations.

CONSTRUCTION TRIGGERS

A critical step in the construction needs analysis process is to determine the most appropriate pavement factors that should be used to indicate the application of pavement construction treatments. The selected set of construction triggers constitutes the basis for all of the other activities used in the construction needs analysis.

Construction triggers may be distress related (i.e., used to identify specific target levels of cracking, roughness, rutting, or friction) or related to capacity of the roadway (i.e., adding lanes to manage increased traffic levels).

THRESHOLD LIMITS

The next step in the process is to set threshold limits on the pavement factors selected as construction triggers. Crossing a threshold limit can indicate the need for a construction treatment. Pavement condition assessment is complicated with the use of hierarchical threshold limits of construction needs for the same condition factor.

PERFORMANCE CURVES

Because the goal of this activity is to plan for future construction events, some form of performance curve is needed to forecast the changes in each construction trigger since the last condition measurement. Performance curves on the rate of change in pavement condition can never be static due to changes in traffic loadings, climate effects, construction techniques and materials, and technology advancement. Keeping pavement performance curves updated with current technology is an apparent intractable problem since long-term observations are generally required to understand how new technology performs.

COLLECTION OF INPUTS

Ideally, pavement management agencies should only collect data needed to support their decisions. Inputs needed to support future pavement construction needs include the condition of construction triggers, explanatory variables used in performance curves, basis of threshold limits, and construction costs.

STRATEGY SELECTION

The strategy selection process is based on future construction needs when the expected condition state of a construction trigger exceeds a threshold limit. Secondary processes include estimation of construction costs and pavement performance expectation after application of each alternative construction treatment so that cost-benefit-based optimization calculations can be performed.

ASSESSMENT AND UPDATE

All management processes require a formal system that documents current procedures, provides an independent assessment of adequacy and compliance with established procedures, and includes an improvement update process to keep them relevant and technologically current. The formal quality management standards developed by national and international agencies can be used as the basis to develop agency-specific protocols.