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TransCAD is the most comprehensive, flexible, and capable
travel demand modeling software ever created. TransCAD supports many styles of travel
demand modeling including sketch planning methods, UTPS-style four-step demand models,
advanced disaggregate modeling techniques, simultaneous models for multiple choices, and
the most extensive set of traffic assignment models ever assembled for use by planners and
traffic engineers.
TransCAD breaks new ground as a tool for transportation planners by streamlining and
improving the demand modeling process. TransCAD is the only package designed to facilitate
the implementation of best practices for travel forecasting and to provide a mechanism for
advancing the state of the art in transportation modeling. Modeling with TransCAD is not
limited to urban or regional demand forecasting, but is directly applicable for modeling
passenger and freight flows at the state, national, and international level.
Demand Forecasting in a GIS Context
Travel forecasting models are used to predict changes in travel patterns and the
utilization of the transportation system in response to changes in regional development,
demographics, and transportation supply. Modeling travel demand is a challenging task, but
one that is required for rational planning and evaluation of transportation systems.
TransCAD is the only planning package that is GIS-based and fully integrates geographic
information system (GIS) and demand modeling capabilities. TransCAD is an extremely
capable and robust GIS that includes many advanced features for transportation that are
not available in other products.
There are many reasons why it is valuable to have a GIS as part of a travel demand
forecasting package. First, GIS makes it possible for planning models to be much more
accurate. For example, network distances are based on the actual shape of the road network
and a correct representation of highway interchanges.
Second, the whole modeling process is more efficient. Data preparation is greatly
facilitated and the database and visualization capabilities catch errors before they cause
modeling problems. With TransCAD, you and others will have an easier time understanding
how the model components behave. For all of these reasons, less staff time is needed to
implement and maintain travel models.
A third important advantage of a GIS-based modeling system is the use of the GIS itself
and GIS-derived measurements directly in the modeling process. In TransCAD, different
modeling equations can easily be derived and applied for different geographic subareas.
Similarly, TransCAD brings new and much-needed capabilities for measuring geographic
accessibility.
Because they have similar architectures, TransCAD is the planning package that integrates
best with other institutional GIS systems. TransCAD can import data from virtually all
major GIS, CAD, and planning software packages. TransCAD is an open system and can export
data in ASCII, shape files, dxf, and dbf formats. TransCAD also links easily to ArcView,
ArcInfo, MapInfo, GIS+, and Maptitude.
SATURN Support
Standard
TransCAD for Great Britain works in
conjunction with SATURN (Simulation and Assignment of Traffic to Urban
Road Networks). Any user with a valid license of SATURN can maintain
databases and set up runs from within TransCAD. TransCAD will also post
process SATURN outputs and present them as tables and map displays.
SATURN is widely used in Great Britain as a
combined simulation and assignment model for the analysis of traffic
management schemes. If you are a SATURN user, the SATURN traffic
assignment interface in TransCAD for Great Britain enables you to run
SATURN simulation/assignment programs, with data preparation and results
displayed in the powerful TransCAD for Great Britain GIS-based platform.
The interface reads the required and optional data prepared into
TransCAD for Great Britain and converts them to SATURN input files, then
calls the appropriate SATURN programs. If SATURN runs successfully, the
interface reads selected SATURN output results back into TransCAD for
Great Britain.
Data preparation in TransCAD for Great Britain is straightforward; for
example, there is no need to enter link and turn data in a given order.
In fact, all the node, link and turn data can be entered in an arbitrary
order. The interface will take care of sorting them as required by
SATURN. The display and analysis of assignment results are conveniently
integrated with the GIS capability of TransCAD for Great Britain. All
SATURN input and output files generated during the process are stored in
your preferred folder, so that you can retrieve them if needed.
Modeling Capabilities
Standard TransCAD includes comprehensive tools for trip generation, trip distribution,
mode split modeling, and traffic assignment. TransCAD includes all of the traditional UTPS
models, quick response models with reduced data requirements, and advanced disaggregate
demand models. Caliper continually enhances TransCAD to incorporate the most up-to-date
methods for demand forecasting.
The
Standard Version of TransCAD includes procedures for:
Freight Applications
Standard TransCAD has been designed to facilitate freight demand modeling as well as
passenger models. An innovative Freight Dashboard™ provides an efficient interface
for retrieving freight flow data by origin, destination, mode, and commodity. TransCAD
offers a complete solution for modeling commodity flows and truck movements. Freight
traffic can be easily assigned to the transportation network and there are also
specialized assignment procedures available for rail waybill assignment.
Programming TransCAD
TransCAD comes with its own application environment and scripting language called
GISDK(TM). GISDK lets you create add-in applications, transportation data and
visualization servers, and web applications.
Innovative Batch Processing
There is an innovative batch processing system that is built in to TransCAD. In addition
to creating scripts the old fashioned way by writing them from scratch, TransCAD lets you
create scripts interactively by clicking menu items, choosing parameters in dialog boxes,
and saving the corresponding script. This can then be edited further in the conventional
manner.
Caliper also provides templates for common modeling streams including feedback so that you
can adapt the templates for your own purposes. The GISDK and the batch facility let you
create beautiful Windows user interfaces for your models.
Linking to other Models
Add-ins can be easily created for TransCAD to customize its use and to link in other
models for post-processing of many types. Caliper provides links to some important
planning applications such as air quality models.
Creating Other Types of TransCAD Applications
TransCAD is an OLE automation server. This means that TransCAD macro functions can be
called from Visual Basic, Visual C++, and other programs. This facilitates the creation of
custom add-ins and stand-alone applications. It also makes it easy to create web
applications.
Advanced Geographic Editing Tools
New editing tools provide an effective means of improving the geography and topology of
planning networks that may have only simple, straight-line representations.
Specifically, Standard TransCAD includes tools for:
• Dualizing, merging, and setting directionality of segments
• Improving the geographical accuracy of line segments through
conflation
• Copying and pasting line segments from one layer to another
• Creating highway interchanges with a minimum of effort.
Consequently, planning networks can now be fully realized as GIS entities and visualized
directly with appropriate accuracy, shape, geometry, and directionality. Many users will
find these tools indispensable for transforming TIGER/Line layers into a suitable basis
for planning and traffic applications as well as for improving the line layers that are
used for other types of transportation, including rail, transit, and air networks.
Data Access and Planning Utilities
TransCAD includes utilities that model builders will find indispensable for data
preparation.
Geocoding: Virtually all forms of survey data can be analyzed in TransCAD. For
most modeling purposes, each survey will be geocoded to the respondent’s primary
location. For traveler surveys, each survey will most commonly be geocoded to their
residence.
Access Census Data Directly: Census data are very valuable in urban
transportation analysis. TransCAD comes with extensive Census data. TransCAD also provides
three procedures for importing specialized Census data. Two of the procedures are for
importing data from the Census Transportation Planning Package (CTPP). The CTPP data are
among the most valuable datasets available for transportation planners. A third procedure
imports TIGER/Line files.
There is also a procedure provided for accessing the Public Use Microdata Samples (PUMS).
PUMS contains complete household records from the US Census for a sample of the
population, and is a valuable source of disaggregate data. The TransCAD procedure
organizes the data so that you can open PUMS files directly and view the data either by
household or by individual.
Import Networks and Trip Tables: TransCAD provides tools for importing networks
and network data from a variety of stand-alone transportation planning packages. These
networks are converted into GIS databases that can be used for all types of planning,
modeling, and mapping applications. TransCAD provides a seamless import capability for
transportation planning network files in MINUTP, EMME/2, TRIPS, QRSII, and TRANPLAN ASCII
format. Usually preprocessing of the original files is not required.
Screenline Analysis: Screenline analysis compares the results of trip assignment
with the traffic counts on roads. More precisely, it is a process of comparing the
directional sum of ground count traffic volumes across a screenline or a cordon line with
the directional sum of the assigned traffic volumes across the same screenline or cordon
line. Screenline analysis is a useful tool for the calibration of trip assignment models,
and it can also be used for more general purposes of calculating flows that cross a
screenline.
Subarea Focusing: While forecasting transportation demand for a region, you may
be interested in performing a more detailed investigation of traffic patterns within a
subarea, such as the downtown area. To facilitate subarea analysis, TransCAD provides a
procedure that lets you create an O-D trip table for that subarea. The reduced O-D table
may be used for performing a traffic assignment on a subarea network which may be more
detailed than the regional network.
Learning TransCAD
TransCAD is easy to learn and use. The documentation teaches travel forecasting and
contains numerous tutorial exercises so that you can explore planning methods on your own.
Caliper also offers frequent training courses in Boston and at customer locations. Many
universities use TransCAD in teaching transporation planning.
Call or
E-MAIL
us to request additional information or a demo CD.
The demo CD is available FREE for
U.S., Canadian, and Mexican customers.
For other
international customers, there is a $50 fee to cover shipping and
handling.
Because of the size of the demo and sample files, it is only
available on CD -- There is no download available.
Order form for
other international Demo CD requests
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