TITLE:
Signalized Corridor Timing Plan Change Assessment Using Connected Vehicle Data
AUTHORS:
Enrique Saldivar-Carranza, Howell Li, Jijo Mathew, Charles Fisher, Darcy Michael Bullock
KEYWORDS:
Adaptive Control, Traffic Signals, Connected Vehicle, Trajectories, Perfor-mance Measures, Before-After
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.12 No.3,
June
20,
2022
ABSTRACT: Updates to traffic signal timing plans are expected to either improve
operations or mitigate the effects of
increased volumes. Longitudinal before-after studies are important when
validating changes to traffic signal systems, but they have historically required field data collection as well as
deployment of extensive detection and communication equipment. These
infrastructure-based techniques are costly and hard to scale. This study
utilizes commercially available connected vehicle (CV) trajectory data to
assess the change in performance between August 2020 and August 2021 on a
22-intersection corridor associated with the implementation of a
semi-automated adaptive control system. Approximately 1 million trajectories
and 13.5 million GPS points are analyzed for weekdays in August 2020 and August
2021. The vehicle trajectory data is used to compute corridor travel times and
linear referenced relative to the far side of each intersection to generate
Purdue Probe Diagrams (PPD). Using the PPDs, operational measurements such as
arrivals on green (AOG), split failures (SF), and downstream blockage (DSB) are
calculated. Additionally, traditional Highway Capacity Manual (HCM) level of
service (LOS) is estimated. Even though there was a 35% increase in annual
average daily traffic (AADT), the weighted average vehicle delay only increased by two seconds, LOS did not change, AOG improved by 1%, and SF and DSB
remained the same. Based on the small changes in operational performance and
considering the increase in traffic volume it is concluded that the
implementation of the semi-automated adaptive control system had a significant
positive impact in the corridor. The presented framework can be utilized by
agencies to use CV data to perform before-after studies to evaluate the impact
of signal timing plan changes. The presented methodology can be applied to any
location where CV trajectory data is available.