Texas A&M's Jack Kong Eyes
Phone Use behavior and Geometrics on Urban and Rural Roads
June 3, 2021
— a notification goes off on a cell phone. A driver looks down and their
eyes briefly leave the road ahead and crash!! Phone use while driving is
a significant source of distracted driving that leads to traffic
accidents, which are considered preventable.
Researchers at Texas A&M University investigated the relationship
between phone use behavior and road geometrics determining that using a
phone while driving is more than just a self-choice. The combination and
presence of a shoulder, median, higher speed limit and extra lanes could
encourage more phone use while driving. The results also confirmed the
correlation between the frequency of phone use and distracted crashes on
This study could help transportation agencies identify countermeasures
on roadways to reducing distracted-related crashes and provide
researchers with a new perspective to study phone-relation behavior
rather than focus on the drivers’ personalities.
“This study finds patterns for where the locations are where phone use
while driving behavior most occurs. These findings are unique and
informative and have not been documented elsewhere yet,” said Xiaoqiang
“Jack” Kong, a doctoral student in the Zachry Department of Civil and
Environmental Engineering and graduate research assistant at the Texas
A&M Transportation Institute (TTI). “While I am driving, I always notice
many drivers who are on their phones talking, texting or scrolling.
There are many times the cars in front of my car didn’t move after
traffic lights turn green. It seems to happen to me every day. As a
transportation Ph.D. student, I started to wonder how exactly this
behavior could impact traffic safety.”
The findings of this study were published in Accident Analysis &
Prevention. The paper’s authors also include Dr. Subasish Das, assistant
research scientist in TTI’s Roadway Safety Division; Dr. Hongmin “Tracy”
Zhou, associate transportation researcher in TTI’s Research and
Implementation Division; and Dr. Yunglong Zhang, professor, associate
department head of graduate programs in civil and environmental
Phone use while driving is a complex psychological behavior driven by
many factors, including the driver’s personality, environmental factors
and roadway operational factors.
From the roadway geometrical perspective, factors contributing to rural
distracted driving cases are dominated by the shoulder width, median
width and the number of lanes. The existence of a shoulder and median or
a wide shoulder and median could encourage phone use behavior since
these geometric features provide a safety buffer for drivers, which
grants drivers a sense of security.
The same factors were true on urban roadways, such as interstates and
freeways. But other contributing factors are traffic volume and access
controls. On an interstate, access control means drivers are entering
and exiting without traffic lights, which could lead to a feeling of
safety and drivers become less cautious or alert.
One challenge facing Kong was obtaining real-world data to reflect
actual phone-use behavior. Evidence showing this kind of case is often
under-reported, and drivers involved in distraction-affected crashes
were reluctant to admit using a phone.
Kong said this study utilized an extensive phone use while driving data
set (pseudonymized), which originated from a private data service
provider. The data collection process is based on a smartphone
application that promotes defensive driving without being distracted by
the phone. The researchers integrated all phone use while driving events
with the Texas road inventory and the distracted crash count on each
road segment in the road inventory from the crash database of Texas.
data does have limitations and might not represent an older population
of drivers who may not download an application to track their driving.
While the most recent road inventory data was used, some data was not
included, such as fixed time or adaptive signalized intersections.
“With more data, researchers may associate this phone use behavior with
drivers’ social demographics. In this way, we may understand this
behavior more at individual levels,” Kong said.
Future research could focus on incorporating the phone use data into
safety performance function models for distraction-affected crashes. As
more data becomes available, building these safety models is possible.
“More visible signs and law enforcement should be placed at these urban
roads with full access control and wide shoulder and medians if these
urban roadways already have higher distracted crash occurrences
comparing with other urban roadways,” Kong said. “Additionally, the
roadways with high-speed variations also being identified as high
distracted crash locations could be the roads that need more attention
from transportation agencies. The countermeasures could improve traffic
conditions or more strict law enforcement.”