Customer: Virginia Department of Transport

Location: Charlottesville, Virginia, United States of America

Service: Comprehensive pavement assessment

Completed: 2017

Historically, Virginia Department of Transport (VDOT) undertook network-level structural assessments of its pavements using a Falling Weight Deflectometer (FWD). An FWD is a stationary testing device, requiring extensive and high-risk traffic control and covers no more than 25 miles per day. Even though it only assessed a small portion of Virginia’s entire roadway system, it took nearly three years to complete.

Therefore, network-wide structural assessment is not particularly feasible utilising this device. This method proved to be excessively inefficient and expensive and more importantly, very high risk from a safety perspective. That meant DOT’s primary and secondary road network, which represent a majority of the lane mileage on Virginia’s highway system, had no recent structural information available.

In 2013 VDOT was a participant in the Traffic Speed Deflectometer (TSD) pooled fund study that investigated the use of a TSD on interstate, primary, and secondary roadways. This study concluded that the TSD was able to survey at a significant increase in efficiency over traditional FWD testing enabling structural testing on a wide range of pavement sections and road classes more feasible. With ARRB bringing its iPAVe equipment and extensive worldwide experience to the United States, this enabled VDOT to conduct a large-scale evaluation on network level structural and functional data.

ARRB Systems performed a comprehensive pavement inventory of 4,400 lane miles of mainline pavements along the Virginia DOT Road Network. This projects goal was to conduct a scaled-up pilot project to determine the ranges of structural parameters that can be generated from a more comprehensive assessment. ARRB was responsible for performing the pre and post validations, quality checks on the collected and processed data, and upload of all data to Hawkeye Insight to enable VDOT VTTI easy access and visualisation of the data for analysis and further research.

The objectives of the project included determining the ranges of pavement structural response or structural index that can be used to differentiate observations of pavement performance and determining the impact of including structural data with functional data from the iPAVe (cracking, rutting, roughness, texture etc.) on VDOT’s pavement management decision making process.

The data generated will be studied for potential inclusion in VDOT’s pavement management. It is envisioned that the results of the project will have the potential to significantly improve the cost-effective management of VDOT’s pavement network. By allowing the pavement management system to account for both the surface condition and structural condition of the pavement system simultaneously, will assist in determining the appropriate district funding levels.