Rolling wheel deflectometer

The RWD was developed by ARA (Applied Research Associates Inc.) in collaboration with FHWA Office of Asset Management in the early 2000s. 

In a recent work on the implementation of RWD in PMS and pavement preservation (Elseifi et al. 2012), it was concluded that RWD deflection measurements were in general agreement and had similar trends to FDW measurements however, the mean centre deflections from the RWD and the FWD were statistically different for 15 of the 16 sites. 

In the same study (Elseifi et al. 2012), a model was developed to estimate SN based on RWD deflection data. Although the developed SN expression based on RWD data was independent of the pavement thickness and layer properties, it was concluded that it provides promising results as an indicator of structural integrity of pavement structure at the network level at the project level, further evaluation of the proposed model was recommended. 

Similar observations were also made in another study assessing continuous pavement deflection measuring technologies (Flintsch et al. 2013). 

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Figure 16.53 Part of RWD semitrailer and illustration of deflection measurement principle, (a) Laser sensors mounted into the trailer body, with enclosure, (b) Illustration of spatially coincident method. (From Elseifi, M. et al.. Implementation of Rolling Wheel Deflectometer [RWD] in PMS and Pavement Preservation. FHWA/11.492. Baton Rogue, LA Department of Civil and Environmental Engineering, Louisiana State University, 2012.)...

FFIWA. 2011. Rolling Wheel Deflectometer Network-Level Pavement Structural Evaluation, Measuring Deflection at Highway Speeds. FHWA, U.S. Department of Transportation. Available at http // www.fhwa.dot.gov/pavement/management/rwd. 

Gedafa D.S., M. Hossain, R. Miller, and D. Steele. 2008. Network level pavement strucmral evaluation using rolling wheel deflectometer. Paper No. 08-2648. 87th Transportation Research Board Annual Meeting. Washington, DC. 

Steele D., J. Hall, R. Stubstad, A. Peekna, and R. Walker. 2009. Development of a high speed rolling wheel deflectometer. 88th Transportation Research Board Annual Meeting. Washington, DC. 

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