Research Description

Infrastructure in the U.S., specifically the national highway system is degrading faster than the federal, state and local agencies are able to financially fix.  According the American Society of Civil Engineers, in order to fix our roads, annual spending would need to increase by $79 billion, or an estimated total investment of $3.6 trillion by 2020. (1)  A deteriorated road can be costly for its users through rutting related vehicle damage, but more importantly, it can also be hazardous for them.  The traffic on our congested roads applies repeated stresses to our roads, which in turn results in rutting and polished surfaces.  Then the polished surfaces create slick conditions when the pavements are wet, but also when they are dry (e.g. at curves).

In 2011, the National HIghway Traffic Safety Administration (NHTSA) emphasized that pavement surface friction “is a key input for highway geometric design,” which is used to determine adequate stopping distances and design speeds, especially along horizontally or vertically curved sections. (2)  As our traffic demand increases (growing population and infrastructural expansion), our roads will continue to deteriorate, creating ever more polished pavements.  We are facing a dire situation, where our roads are performing far below design standards which is resulting in pavements with a declining safety performance.

In our country, “motor vehicle crashes remain the third leading cause of death among ages 5 to 34”, falling just short of cancer and heart disease. (3)  In 2015, there were approximately 35,000 fatalities and 4.4 million injuries related to vehicle crashes in the U.S.. (4, 5)  These numbers should be alarming, thus asserting the need for further prevention through improvements to the current practice of evaluating the safety performance of our roads.  In transportation engineering, the safety performance of a roadway is used to assess the need for road repair through assessing the roadways associated crash risk.  Currently, the Federal Highway Administration (FHWA) models crash risk as a function of traffic.  The purpose of my research is to accentuate to the FHWA the need for monitoring and managing the safety performance of the national highway system as a function of traffic, but also a function of pavement surface friction (in addition to other characteristics).

The current project I’m working on is funded by the FHWA.  The goal is to assist fours state Departments of Transportation (DOTs) in the management of their roadways using state-of-the-art technology (a Sideway-Force Coefficient Routine Investigation Machine).  Using this technology, a plethora of pavement properties (e.g. surface friction, etc.) can be measured continuously along an entire pavement network.  With the collected data, the safety performance prediction models can be generated, which if successful, should improve our current understanding of how crashes occur.  With a better understanding of crashes, DOTs will be able to make more efficient management decisions in the future, resulting in a decrease in the number of annual vehicle crashes that result in either serious injuries or fatalities.

  1. 2013 Report Card for America’s Infrastructure.  Accessed April 8, 2016.
  2. Traffic Safety Facts 2011: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System.  National Highway Traffic Safety Administration and the U.S. Department of Transportation, Washington, D.C., 2011.
  3. Cambridge Systematics, Inc.  Crashes vs. Congestion: What’s the Cost to Society?  The American Automobile Association, 2011.
  4. Lyles, D.  Traffic Fatalities Fall in 2014, but Early Estimates Show 2015 Trending Higher, November 24, 2015.  Accessed April 8, 2016.
  5. Ziv, S.  U.S. Traffic Deaths, Injuring and Related Costs Up In 2015, August 17, 2015.  Accessed April 8, 2016.