TITLE:
Traffic Flow Characteristics in Work Zone and Non-Work Zone Environment and Its Impact on Road Crashes at the Segment Level
AUTHORS:
Dorcas O. Okaidjah, Christopher M. Day
KEYWORDS:
Probe Data, Congestion Mile Hours, Queue Mile Hours, Speed Deficit, Crashes, Work Zones
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.13 No.4,
September
20,
2023
ABSTRACT: This study investigates relationships between congestion and travel time
performance metrics and crashes on road segments. The study focuses on work
zone routes in Iowa, utilizing 2021 commercially-available probe vehicle data
and crash data. Travel time performance metrics were derived from the probe
vehicle data, and crash counts were obtained from the crash data. Additional
variables included road characteristics (traffic volume, road type, segment
length) and a categorical variable for the presence of a work zone. A mixed
effect linear regression model was employed to identify relationships between
road segment crash counts and the selected performance metrics. This was
accomplished for two sets of models that include congestion performance
measures at different defining threshold values, along with travel time
performance measures. The study results indicate that the congestion
indicators, certain travel time performance measures, and traffic counts were
statistically significant and positively correlated with crash counts.
Indicator variables for rural interstate locations and non-active work zones
have a stronger influence on crash count than those for municipal interstate
locations and active work zones. These findings can inform decision-makers on work
zone safety strategies and crash mitigation planning, especially in high
traffic volume areas prone to congestion and queues.