Corridor Analysis: The Common Sense Approach to Road Repair

Project Background

What’s the most cost effective way for a Department of Transportation (DOT) to plan for future pavement repairs – especially on a high-traveled, lengthy roadway?  Three years ago, Texas A&M Transportation Institute (TTI) researchers completed an investigation of the entire 160 miles of the I-20 corridor in the Odessa District. In order to help TxDOT determine which sections needed immediate repair and which sections would likely last for years, the researchers utilized the various pavement evaluation tools they developed over the last two decades and prepared an extensive 10-year rehabilitation plan  for the entire corridor.

What’s the Problem?

We all know that money is tight in the road maintenance business. To complicate matters, keeping track of the performance history of each section of a high-volume thoroughfare is a daunting task. In most cases, a visual inspection is not a good predictor of when a pavement might fail.  All too often, maintenance activities make a road visually look fine, but these thin treatments cannot fix roadways with major structural deficiencies. Selecting the best rehabilitation alternative requires DOT’s to use the available nondestructive test equipment, together with focused field coring, to identify the cause of pavement failures.  Once the true cause of the pavement problem is identified, the optimal rehabilitation strategy can be readily defined.   

What’s the Solution?

TTI researchers conducted an extensive evaluation by dividing the I-20 corridor into 16 sections. The pavement conditions in each section were evaluated by using Ground Penetrating Radar, Falling Weight Deflectometers, core samples, and laboratory analysis tools. Researchers collected traffic volume data, compiled maintenance histories for each section, and took into account the local road project priorities. After evaluating all the data, researchers categorized pavement conditions and recommended an optimum rehabilitation strategy.  The urgency of repair was prioritized into four groups: those that needed attention during the next two years, from two to five years, from five to ten years, and those pavement sections expected to last more than 10 years.  District designers were provided these recommendations, along with details of the testing and decision approaches used, in a focused report and presentations.

Has it Paid Off?

The TTI recommendations were implemented in the Odessa district.  In one project the pavement problems were focused in the outside travel lanes, whereas the inside lanes were in good condition. Subsequently, the available funds were focused on repairing the most severe problems.  Only minimal treatments were applied to the inside lane, and TxDOT officials claim millions of taxpayers’ dollars were saved. Similar corridor analysis projects were conducted in Lubbock and Bryan, with other studies currently underway in the Pharr and Atlanta Districts.