Rutgers Pavement Resource Center – Ride Quality Tools

Download Final Report

CAIT project no.: 192 RU8485

Fiscal Year: 2006/2007

Status: Final

Rutgers-CAIT Author(s): Thomas Bennert, Ph.D., Nicholas Vitillo, Ph.D., Patrick Szary, Ph.D. and Nenad Gucunski, Ph.D.

External Author(s): Sue Gresavage, NJDOT



The Pavement Technology Unit had been inundated with requests from contractors to provide International Roughness Index (IRI) testing during various construction phases. With the release of the NJDOT Ride Quality specification, contractors can receive a financial penalty or bonus depending on the IRI values of the pavement surface after the final surface course has been placed and compacted. However, many of these contractors have been asking for testing of the intermediate layers during construction, in an attempt to validate the smoothness of these layers prior to the placement of the final surface layer.

In an effort to support these requests and improve the final pavement smoothness, the Pavement Technology Unit has requested the evaluation and implementation of portable walk-behind pavement surface profile measurement devices that can determine the IRI of intermediate units as requested. After evaluation, the selected portable walk-behind pavement surface profile measurement device were recommended and implemented by the NJDOT Regional offices to provide on-site support to the asphalt industry. The tasks performed include:

  • Evaluation of current walk behind systems
  • Purchase of four walk behind systems based on initial evaluation
  • Training of central pavement and material engineers and region materials engineers on the walk-behind systems (data collection, maintenance, and analysis)
  • Purchase a bare minimum high speed profile that contains texture lasers.
    – Modify the system to incorporate video, GPS, rut bar measurements and additional flexibility for future additions (tire/pavement noise)
    o Require shock mounting on racks because boards popping out – may want to mount horizontally instead of vertically (more problems occurring on computers on top of racks)
    o Consolidate the digital cameras control and storage on one computer
    o Interview Pavement Tech. staff to discuss reoccurring mechanical problems with current technology
    o Prepare Specification for transport vehicle (e.g., Ford chateau van model).