Optimizing Highway Funds by Integrating RWD Data into Pavement Management Decision Making
Pavement structural response is an important indicator of pavement structural capacity, which influences performance measures, such as cracking. Traditionally, pavement management systems have tracked performance using condition indices based on visual distress; however, condition indices based on surface conditions only do not provide a measure of pavement structural response, and therefore, an estimate of pavement structural capacity. The Rolling Wheel Deflectometer (RWD) is an innovative device that efficiently collects network-level pavement structural response produced by an18-kip single axle semi-trailer load traveling at normal highway speeds. This makes the RWD highly productive and eliminates the need for lane closures, which increases the safety and mobility of the traveling public. Applied Research Associates, Inc. (ARA) collaborated with the Oklahoma Department of Transportation (ODOT) to study the potential benefit of integrating RWD data in their pavement management process. The study included RWD data collection on over 1,000 miles of ODOT highways, processing to determine representative pavement deflections for each Pavement Management System (PMS) section, incorporation of structural index in their decision tree, and generation of rehabilitation plans with and without the structural index to evaluate their effect on management decisions and the optimization of highway funds. The results showed a significant cost savings when incorporating the RWD-based structural index, primarily due to the use of more cost-effective pavement preservation techniques on pavement sections with good structural response (i.e., low deflections). In addition, the strategy incorporating the RWD-based structural index made better use of funding by delaying treatment on roads with poor structural response until pavement rehabilitation was a cost-effective option.