21 April 2006 - Next Generation Simulation at FHWA
During the past two days, we hosted
James Colyar, former UI student (BSCE, 1995) and currently a
transportation research engineer with the Federal Highway
Administration's Turner Fairbank Highway Research Center in
McLean, Virginia. The purpose of the visit was to introduce
James to our transportation research and education programs
and to learn more about FHWA’s work in the development and
support of traffic analysis tools and simulation.
In a presentation to one of our
graduate classes in transportation, James described FHWA’s
new role in traffic analysis tools as complementing that of
the private sector. While the private sector will develop
the user interface that wraps around the modeling tools,
FHWA will support the basic research for the driver behavior
algorithms that are the basis of these tools. They
will also support the development of the data bases that are
needed for this research. FHWA will no longer be in the
model development business, but will support the research
needed for the next generation of simulation models. CORSIM,
long-supported by FHWA, will now be licensed to McTrans at
the University of Florida. McTrans will guide future
development of CORSIM.
FHWA is now completing a six volume
traffic analysis toolbox that will support end users as they
determine which tools are most appropriate to the problems
that they need to solve and with guidance on the use of
simulation models. James noted that “better models enable
better decisions”, and that their toolbox will do just that.
Here is a link to their traffic analysis toolkit:
http://ops.fhwa.dot.gov/trafficanalysistools/toolbox.htm.
FHWA’s support of simulation models is
now through the NGSIM project. The purpose of the NGSIM
(for “next generation simulation models”) project is to
improve the quality, trust, and use of simulation tools.
The end products from NGSIM are (1) better driver behavior
algorithms, (2) new data sets that support the algorithm
development, and (3) free access to both the algorithms and
data sets. The first new algorithm, a new lane changing
model, is now being tested in the VISSIM, Paramics, and
Aimsun simulation models. VISSIM is
marketed by one of NIATT's partners, PTV America. Three
stakeholder groups are represented in the project: traffic
modelers, software developers, and model users.
FHWA has released four data sets as
part of the NGSIM project. The data sets, as well as other
information on the project, can be found at
www.ngsim.fhwa.dot.gov. The data were collected using
very high resolution cameras, located on buildings that are
at least 20 stories high, to provide a complete visual
perspective of the highway segment under study. Vehicle
records are at 0.1 second resolution, with positions
accurate to within one foot. The x/y coordinate location
for a vehicle is by its front bumper. The newest data set
(just released last week) includes 30 minutes of data for an
arterial in Los Angeles, with 4 signalized intersections.
Signal timing status is at one second resolution. This
arterial data set is relevant to work that we are doing at
NIATT on traffic signal control and operations, particularly
in our work to better understand the role of traffic signal
timing parameters on intersection operations and in the
selection of the appropriate intersection measures of
effectiveness.
NGSIM data are being extracted using
new image processing software. The NG-video process
includes data collection using the high resolution cameras,
image processing, trajectory extraction, and post processing
and error checking. The camera resolution required for this
processing is one pixel per foot.
You can review the presentations that
James Colyar made during his visit at the following links:
Oversaturated Freeway Flow Algorithm: Research Plan
FHWA Traffic Analysis Tools & NGSIM Program
Careers in Transportation & FHWA
You can also contact James if you have
further questions on his work at
James.Colyar@fhwa.dot.gov. |
