Commercial Operations

In this paper, we develop a simulation optimization procedure for optimizing the urban
arterial traffic signal timings including a bunch of sequential intersections. The system
performance is estimated via a stochastic discrete-event meso-scopic traffic simulator, and a
gradient-based search algorithm on stochastic approximation is applied to give the optimal
signal timings. Simultaneous perturbation analysis is used to derive both left-hand and righthand
gradient estimators of the system performance with respect to the cycle lengths, green
splits, and green offsets for those intersections within the arterial. Numerical experiments
show that the meso-scopic traffic simulator provides reasonable system performance in much
less running time if properly calibrated, compared with a widely-used commercial traffic
microscopic simulation program CORSIM. In particular, for all scenarios designed, the
optimizer converges to optimal signal timing plans which significantly increase the system
performance.

University of Maryland, College Park

Presented at the ITS America Annual Conference and Exposition, November 16-20, 2008, New York, New York

A simulation of vehicle infrastructure integration (VII) implementation for highway rail grade crossings (HRGCs) is constructed. The driver behavior, vehicle maneuvering, and communication characteristics are considered by providing a user interface for updating parameters of the vehicle, train, latency, and simulation. The simulation emulates communication standards of the railroad, roadway, and vehicle system. Instead of simulating the send-and-receive process of dedicated short range communication (DSRC), the eventual latency is emulated. The mobility improvement is significant in terms of delays, travel times, and queue lengths, with the implementation of simple vehicle control logics. As the train information is provided to VII vehicles, the drivers are able to respond to avoid complete stops in a queue. The transmission range and market penetration rate are key issues for future implementation. The simulation results indicate that longer transmission ranges and higher market penetration rates will be beneficial to mobility improvement.

University of Nebraska-Lincoln

Presented at the ITS America Annual Conference and Exposition, May 3-5, 2010, Houston, Texas

This paper addresses an analytical model for estimating traffic parameters on a grid  network
of urban streets. By proposing 2 route choice models, we try to provide a simple expression of
directional traffic flows on different kinds of intersections within a grid network, following its
fundamental hierarchical structure.  Our main purpose is to simplify macroscopic traffic
simulation. The proposed analytical model can be used to estimate traffic parameters on roads
with relatively less interest in a simulation study.  A comparison study with  macroscopic
traffic simulation results is also carried on, which is utilized as the validation of the analytical
model finally.

Kuwahara Laboratory, Institute of Industrial Science, University of Tokyo

Presented at the ITS America Annual Conference and Exposition, November 16-20, 2008, New York, New York

This study aims to achieve an efficient snow removal task by applying developed ITS
technologies and Human Machine Interface to snowplow. This paper describes the analysis of
snow removal operation on sidewalk, the mechanical type of rotary snowplow on sidewalk,
and proposes a side slip control system considering the characteristics of the snowplow
behavior to improve the longitudinal stability during operation, which is expected to be
practically used in near future.

The University of Tokyo

Presented at the ITS America Annual Conference and Exposition, November 16-20, 2008, New York, New York

In recent years, road owners have shown an increased interest in implementing road user
charging schemes based not on the traditional tag and beacon technology known from
highway tolling, but instead using autonomous onboard equipment, capable of measuring road
usage without the assistance of omnipresent road side equipment. This change in technology
makes the earlier approach to interoperability insufficient, and a new set of principles must be
established. This paper presents a set of such principles and how they can work to create
incentives for actors to prioritize interoperability, while at the same time provide for
continuous innovation and competition in the marketplace.

Royal Institute of Technology

Presented at the 15th World Congress on Intelligent Transport Systems, November 16-20, 2008, New York, New York