Asphalt Pavement Magazine - May/June 2018 - 29

© PHOTOS COURTESY CARSTEN KARCHER AND FAN GUO

In 2017, NAPA and the European Asphalt
Pavement Association (EAPA) co-hosted
the European Asphalt Rolling Resistance
Workshop in Brussels, Belgium. The event
was developed to help both organizations
gain a better understanding of how asphalt
pavements and mixtures can impact the
rolling resistance of vehicles.

carbon emission in all facets of a
pavement's life, including the use
phase. To aid in this, a low rolling
resistance stone mastic, or matrix,
asphalt (SMA) has been designed.
Through research, the mix has
been designed for environmental
performance and durability.
Denmark has committed to paving
at least 50 km of this low rolling
resistance mixture in 2018.
The second presentation that
afternoon focused on a roundrobin test conducted in Nantes,
France, which compared different
rolling resistance devices. Overall,
the rolling resistance device
from the Technical University of
Gdansk (TUG) and Belgian Road
Research Center (BRRC) showed
the most consistency and accuracy.
Both devices measure rolling
resistance through an angle-based
system instead of a force-based
methodology.
After the presentations,
workshop participants were
compelled to discuss a path
forward in order to meet the

challenges of measuring rolling
resistance. Ultimately, models
will be needed in order to assess
rolling resistance over a network
of pavements; however, these
models must be validated to realworld measurements. Despite
the unknowns still surrounding
rolling resistance, in 2016, EAPA,
the European Concrete Industry
(EUPAVE), and the association of
laboratories in Europe (FEHRL)
developed a position paper
designed to highlight the most
effective way of reducing carbon
emissions on roadways. All three
associations came together and
focused on maintaining and
upgrading pavement condition.
For countries, including the
United States, to truly see the
impact rolling resistance could
have on emissions, it is critical that
infrastructure is funded to allow
for the maintenance of smoothness
and texture. In December 2017, a
workshop similar to the European
Asphalt Rolling Resistance Workshop
was held in Chicago, Ill. to highlight

what research is being conducted
in the U.S. on this topic. Drs. Imad
Al-Qadi (University of Illinois), John
Harvey (University of California at
Davis), Gerardo Flintsch (Virginia
Tech), Karim Chatti (Michigan State
University), and Bernard Izevbekhai
(Minnesota DOT) all participated in
this meeting.
North American rolling resistance
research, which is more focused on
modeling the impacts of pavement
properties such as pavement
smoothness, texture, and stiffness,
has showed a less significant impact
on texture compared to European
research. This difference, however,
may be due to the methods used
to quantify texture. Additionally,
some research has shown that
pavement stiffness may have a small
impact on rolling resistance, but
this impact would be seen on only
a small number of pavements in
very specific conditions (i.e., those
subjected to very heavy trucks, slow
traffic, and high temperatures).
Research in Illinois suggests,
however, that tire deflection is more
critical than pavement deflection in
the modeling because the tire will
deflect much more than pavement
itself. Overall, North American
research showed that smoothness
is the most critical pavement
property that can impact vehicle
fuel economy.
In conclusion, if funding cannot
be secured to keep the roads in
their proper condition, then we will
continue to miss an opportunity
to reduce CO2 emissions resulting
from the use of our pavements. AP
Dr. J. Richard Willis is Director of
Engineering and Innovation at NAPA.
He can be contacted at
RWillis@AsphaltPavement.org.

Asphalt Pavement Magazine - May/June 2018 * 29



Table of Contents for the Digital Edition of Asphalt Pavement Magazine - May/June 2018

Chairman’s Commentary
Industry News
Tools for the Trade
A Green Answer for Higher Recycling
Reducing Rolling Resistance to Reduce Emissions
Recycled Tire Rubber Mixture Yields High-Performing Road
The Pavement Economics Committee: A Powerful Partnership
Focus on the Field: Job Spotlight
Industry Events
Index of Advertisers/Advertisers.com
Perspectives
Asphalt Pavement Magazine - May/June 2018 - intro
Asphalt Pavement Magazine - May/June 2018 - cover1
Asphalt Pavement Magazine - May/June 2018 - cover2
Asphalt Pavement Magazine - May/June 2018 - 3
Asphalt Pavement Magazine - May/June 2018 - 4
Asphalt Pavement Magazine - May/June 2018 - 5
Asphalt Pavement Magazine - May/June 2018 - 6
Asphalt Pavement Magazine - May/June 2018 - 7
Asphalt Pavement Magazine - May/June 2018 - 8
Asphalt Pavement Magazine - May/June 2018 - Chairman’s Commentary
Asphalt Pavement Magazine - May/June 2018 - 10
Asphalt Pavement Magazine - May/June 2018 - Industry News
Asphalt Pavement Magazine - May/June 2018 - 12
Asphalt Pavement Magazine - May/June 2018 - 13
Asphalt Pavement Magazine - May/June 2018 - 14
Asphalt Pavement Magazine - May/June 2018 - 15
Asphalt Pavement Magazine - May/June 2018 - 16
Asphalt Pavement Magazine - May/June 2018 - 17
Asphalt Pavement Magazine - May/June 2018 - Tools for the Trade
Asphalt Pavement Magazine - May/June 2018 - 19
Asphalt Pavement Magazine - May/June 2018 - 20
Asphalt Pavement Magazine - May/June 2018 - 21
Asphalt Pavement Magazine - May/June 2018 - A Green Answer for Higher Recycling
Asphalt Pavement Magazine - May/June 2018 - 23
Asphalt Pavement Magazine - May/June 2018 - 24
Asphalt Pavement Magazine - May/June 2018 - 25
Asphalt Pavement Magazine - May/June 2018 - 26
Asphalt Pavement Magazine - May/June 2018 - 27
Asphalt Pavement Magazine - May/June 2018 - Reducing Rolling Resistance to Reduce Emissions
Asphalt Pavement Magazine - May/June 2018 - 29
Asphalt Pavement Magazine - May/June 2018 - 30
Asphalt Pavement Magazine - May/June 2018 - 31
Asphalt Pavement Magazine - May/June 2018 - Recycled Tire Rubber Mixture Yields High-Performing Road
Asphalt Pavement Magazine - May/June 2018 - 33
Asphalt Pavement Magazine - May/June 2018 - 34
Asphalt Pavement Magazine - May/June 2018 - 35
Asphalt Pavement Magazine - May/June 2018 - 36
Asphalt Pavement Magazine - May/June 2018 - 37
Asphalt Pavement Magazine - May/June 2018 - 38
Asphalt Pavement Magazine - May/June 2018 - 39
Asphalt Pavement Magazine - May/June 2018 - The Pavement Economics Committee: A Powerful Partnership
Asphalt Pavement Magazine - May/June 2018 - 41
Asphalt Pavement Magazine - May/June 2018 - 42
Asphalt Pavement Magazine - May/June 2018 - 43
Asphalt Pavement Magazine - May/June 2018 - 44
Asphalt Pavement Magazine - May/June 2018 - 45
Asphalt Pavement Magazine - May/June 2018 - 46
Asphalt Pavement Magazine - May/June 2018 - 47
Asphalt Pavement Magazine - May/June 2018 - Focus on the Field: Job Spotlight
Asphalt Pavement Magazine - May/June 2018 - 49
Asphalt Pavement Magazine - May/June 2018 - 50
Asphalt Pavement Magazine - May/June 2018 - 51
Asphalt Pavement Magazine - May/June 2018 - Industry Events
Asphalt Pavement Magazine - May/June 2018 - 53
Asphalt Pavement Magazine - May/June 2018 - 54
Asphalt Pavement Magazine - May/June 2018 - Index of Advertisers/Advertisers.com
Asphalt Pavement Magazine - May/June 2018 - 56
Asphalt Pavement Magazine - May/June 2018 - 57
Asphalt Pavement Magazine - May/June 2018 - Perspectives
Asphalt Pavement Magazine - May/June 2018 - cover3
Asphalt Pavement Magazine - May/June 2018 - cover4
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