Naonal Center for Asphalt Technology and i-Probe carry out Data

Collecon Studies

The Naonal Center for Asphalt Technology in Auburn, Alabama conducts test track experiments with i-Probe

to evaluate i-Probe’s pavement scanning accuracy and correlaon of outputs to other road roughness indices.

October 8, 2024 – AUBURN, Alabama

The Naonal Center for Asphalt Technology (NCAT), which operates its own test track in Opelika, AL

for asphalt pavement research, hosted an experimental evaluaon of i-Probe technology on October 8.

inspecon vehicle, which is the typical equipment used for measuring pavement condion. This baseline

data would then be compared to i-Probe’s readings to determine the correlaon. Addional trials were

also carried out on a nearby stretch of open road that is paved in concrete to determine any dierences

from the readings of the asphalt-paved test track surface.

The most common index for measuring

roughness is the Internaonal Roughness

Index (IRI). IRI is calculated based on

cumulave vercal displacement of a

simulated single car wheel (quarter-car)

model with suspension system divided by

modern cars. This sensor detects the

ineral movement of the vehicle in all

direcons. Road roughness is determined by

isolang only vercal movement, and assigning a score based on the magnitude of vercal displacement.

This measurement is known as ride quality. The lower the score, the smoother the road.

Although both indices capture the same informaon, the diering calculaon methodologies can be

problemac. Road management agencies in the US are required to report road condions to the federal

government based on IRI. Being able to output and integrate data within the same index standard is

vital to the instrumentality of i-Probe. This experiment was intended to ascertain this correlaon as a

rst step to data integraon.