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Increase in Roughness Due to Environmental Factors in Flexible Pavements

Project Information

Project ID: 
Project Status: 
Start Date: 
Wednesday, July 23, 2014
End Date: 
Monday, January 23, 2017
FHWA Program: 
FHWA Subprogram: 
Long-Term Infrastructure Performance
FHWA Activity: 
Long-Term Pavement Performance
FHWA Topics: 
Roads and Bridges--Pavement and Materials
TRT Terms: 
Pavement Performance; Research; Smoothness; Infrastructure; Pavements; Flexibility
FHWA Discipline: 
Pavement and Materials
TRB Subject Area: 
Pavements, Research

Contact Information

First Name: 
Larry J
Last Name: 
(202) 493-3079
Email Address: 
Long-Term Infrastructure Performance Team
Office of Infrastructure Research and Development
Office Code: 

Project Details

Project Description: 

The project is aimed at investigating the increase in roughness of flexible pavements due only to environmental factors. In the Long-Term Pavement Performance (LTPP) program, starting with the use of the inertial profiler in 1996, profile data have been collected along the two wheelpaths as well as along the center of the lane. The data collected along the center of the lane are not available in the LTPP database. However, the data are available in AIMS (Ancillary Information Management System). When evaluating the changes in roughness that occurs along a wheelpath, effects of the environment cannot be separated from traffic effects. The profile data collected along the center of the lane can be used to evaluate the change in roughness that is only due to environmental effects. Environmental effects can cause changes in the moisture content of the subgrade from the as-constructed value, which can cause the subgrade to shrink or swell. Freezing temperatures can cause frost heave. All of these factors can cause a change in the profile of a pavement, thereby increasing the roughness. The analysis will be performed on the test sections contained in SPS-1 [Specific Pavement Study] projects. This project will provide information on how environmental conditions interact with subgrade conditions and influence increase in roughness for the different pavement structures that are present on a SPS-1 project. The different pavement structures in a SPS-1 project have different material being used for base layers, including a drainage layer (i.e., permeable asphalt-treated base) in some sections.


The project will investigate and report the findings of the increase in roughness of flexible pavements due to environmental factors.

Partners and Other Sponsor/Managing/Performing Organizations: 


Deliverable Name: 
Final report and related material.
Deliverable Type: 
Research report or guidelines
Deliverable Description: 
A final report documenting the results from the analysis will be prepared. A TechBrief documenting the findings from the research will be prepared. Anticipate preparing a paper to be submitted to the Transportation Research Board (TRB) Annual Meeting describing the findings from this research project. A DVD containing the files that were used for analysis will be provided so that the profile data used for the analysis will be available to other researchers.