Intelligent compaction (IC) technique is a fast-developing technology for compaction quality control and acceptance. Proof rolling using the intelligent compaction rollers after completing compaction can effectively identify the weak spots and significantly improve the uniformity of the compacted layers.  The IC technology is currently being improved at a rapid pace. The Federal Highway Administration, which is funding a large number of demonstration projects throughout the US, has accumulated all the current specifications and has developed excellent visualization and analysis tools related to the IC technology (see http://www.intelligentcompaction.com). Despite many federal and state funded  studies to implement the IC technology, there are still  obstacles and gaps that need to be explored and overcome in order to fully employ this technology in the day-to-day operations.  What is fundamentally missing from most efforts is an attempt to understand the behavior of the IC roller responses and their correlations to the other modulus-based devices such as Dynamic Cone Penetrometer (DCP), Lightweight Deflectometer (LWD), Plate Load Test (PLT), and Falling Weight Deflectometer (FWD).