Commercial Operations

Sampling is a fundamental component of probe based traffic monitoring. The quality of
traffic parameter estimates generated through this method is highly dependent on the choice
of the sample set. In sampling of probe vehicle data, care has to be taken to select appropriate
number of samples without compromising requirements of cost of data collection and
accuracy of estimated parameters. Choice of sampling methods and determination of sample
sizes are important aspects that require careful study for sampling design implementation.
This paper describes a research effort that investigates stratified sampling as a well suited
sampling method for probe based traffic monitoring.   Choice of stratification variables,
determination of strata boundaries and allocation of sample sizes to strata for a traffic
network is discussed.

University of Virginia

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

Sampling is a fundamental component of probe based traffic monitoring. The quality of
traffic parameter estimates generated through this method is highly dependent on the choice
of the sample set. In sampling of probe vehicle data, care has to be taken to select appropriate
number of samples without compromising requirements of cost of data collection and
accuracy of estimated parameters. Choice of sampling methods and determination of sample
sizes are important aspects that require careful study for sampling design implementation.
This paper describes a research effort that investigates stratified sampling as a well suited
sampling method for probe based traffic monitoring. Choice of stratification variables,
determination of strata boundaries and allocation of sample sizes to strata for a traffic
network is discussed.

University of Virginia

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

In the light of increasing demand for further application of Variable Speed Limit
(VSL) Control Systems, it is essential to ensure that these systems are robust enough to
produce the impacts required to meet the specific objectives set for their implementation. The
extent of success of VSL Systems largely depends on the underlying approaches and methods
used in their algorithms logic. In this article, first a critical review of different approaches and
methods for VSL with emphasis on those currently implemented in real world is made. Then
based on an assessment of the performance of existing systems especially the UK system
(known as Controlled Motorways), a number of suggestions for further improvements to the
existing rule-based practical systems is made. Considering the limitations inherited in the
currently used practical systems, merits for the development and application of new networkoriented
VSL systems based on robust theoretical control models and/or artificial intelligence
techniques are highlighted.

Yazd University

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

Bus stops are key links in the journeys of disabled bus riders.  Inaccessible
bus stops prevent people with disabilities from using fixed-route bus services, thus limiting
their mobility.  Due to limited budgets, transit agencies must select bus stops for which their
improvements, as part of the effort to comply with the Americans Disabilities Act (ADA),
can maximize the overall benefits to patrons with disabilities.  Based on an analysis of 5,034
bus stops in Broward County, Florida, a GIS-based decision support system for allocating bus
stop improvements for riders with disabilities was developed and is described in this paper.  
An analytic hierarchy process was applied to combine all of the factors that affect optimum
investment decisions, and a binary linear programming model was used to determine a
priority list of bus stop improvements based on budgetary and construction cost constraints.

Florida International University

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

For many years, freeway traffic management programs have been focused on the large
metropolitan areas. In upstate New York, one of the State’s ITS deployments is a
program to manage transportation incidents in both a mid-sized urban and rural area,
utilizing a scaled-down version of a “big city” ITS implementation. The real backbone of
this program is a number of multi-jurisdictional operational relationships focused through
a Transportation Management Center.
In 1999, the New York State Police and New York State Department of Transportation
opened a co-located Transportation Management Center in Albany, NY. In conjunction
with this, two Traffic Task Forces, for the Capital and Southern Adirondack regions,
have been established with 29 additional State and local agency partners. While all the
agencies have accepted the documented detour and response plans for transportation
incidents in the area, almost all of these partnerships are informal. Member agencies
are allocating resources to the program through their personnel involvement, but the
Task Forces are not receiving any funds. It has been purposely kept “simple” to avoid
the red tape of legal agreements and funding. It is a group of operations personnel
doing what they do best to get the job done with available resources and support from
their management.

New York State Department of Transportation

Presented at the ITS America Annual Conference and Exposition, April 29-May 2, 2002, Long Beach, California