| Summary: | Traffic platoons created by traffic signals may have impacts on the operations of
downstream intersections because they change the arrival pattern and gap distribution of
upstream traffic. There’s been a lot of research dealing with platoon effects on
operations at signalized intersections, while very limited research has been done for that
of unsignalized intersections.
This research aims to develop a methodology for analyzing the platoon impacts
on major-street left-turn (MSLT) delay at two-way stop-controlled (TWSC)
intersections. The main idea is using a microscopic simulation tool to simulate different
platoon scenarios in opposing through traffic, then applying regression models to capture
the impacts of platoons on the delay of MSLT. Two platoon variables were adopted as a
simplification of the complex platoon scenarios, making it practical to analyze the
platoon effects on MSLT delay.
The first two steps were to build simulation models for real-world unsignalized
intersections and simulate scenarios with a combination of various factors related to
platoons in VISSIM simulation. Calibrations of these simulation models based on field data were performed before simulation started. The next step was to define, derive and
calibrate two platoon variables for describing the duration and intensity of platoon
arrivals in the opposing through traffic, which effectively simplified the large
combination of various factors. At last, the two platoon variables and their relationship
with MSLT delay change factor were modeled with regression tools. A relationship
between the two variables and the delay change factor was established, which indicated
a positive effect by upstream platoons on MSLT delay and made it possible to quantify
the impacts. The findings in this research could also be used for future research on left turn
treatment regarding platoon or signal impacts.
|
|---|
