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Current & Recent Research
Economic
Impact Study of the Intercounty Connector
Dr. Mahmassani and Dr. Clifton conducted, for theMaryland
State Highway Administration (SHA), a project planning study to
analyze alternatives for a state-of-the-art, limited access, east-west
highway linking I-270 to I-95 (Intercounty Connector, or ICC). The
potential economic impact of this project, under different possible
alternative configurations, is a major consideration in assessing
its overall desirability as well as the relative merit of the contemplated
alternatives. The economic impact study performed by the Maryland
Transportation Initiative (MTI) at the University of Maryland addressed
the two Build Alternatives (Corridors I and II) presently defined
for the ICC project. Its principal objectives were to (1) estimate
the travel efficiency savings likely to accrue to the facility users
as well as to residents and businesses of the affected communities,
and (2) assess the type and magnitude of the economic development
impacts that may occur due to the construction of an Intercounty
Connector and resulting travel efficiencies. You may find more infomation
at MD
SHA's ICC site. Click here for the MTI
Summary Report on the Economic Impact of the ICC; you may also
download the full technical report.
Researchers: Hani S. Mahmassani, Kelly Clifton
2004
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Freight and Logistics Considerations: Intercounty Connector
Economic Impacts
Dr. Elise Miller-Hooks and Dr. Larry
Bodin (Emeritus Professor in the R. L. Smith Graduate School of
Business), in collaboration with Dr. Hani Mahmassani, have conducted
a study to assess the impacts of a proposed Intercounty Connector
(ICC) in Maryland's Montgomery and Prince George's County on freight
and logistics operations in the region. The study relies on interviews
with selected shippers and carriers in the region, coupled with
an analysis, using actual company data, of how freight movement
and distribution might change with the proposed new facility. The
study also addresses how the proposed new facility might impact
the relative importance of the region's airports for freight and
logistics operations. A
copy of the report is available here.
Researchers: Elise Miller-Hooks, Larry Bodin, Hani S.
Mahmassani
2004
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Development
and Testing of a Real-Time Traffic Estimation and Prediction System.
This recently completed project, funded by the US Federal Highway
Administration as part of their Intelligent Transportation Systems
research and development program, developed the first simulation-based
dynamic traffic assignment methodology for real-time traffic estimation
and prediction in intended for application in advanced traffic management
centers. The system, called DYNASMART-X, interfaces with data from
road sensors and other real-time information sources, to model traffic
evolution through an entire regional or urban traffic network and
generate predictions of the network state over the horizon of interest.
These form the basis for travel time predictions for advanced traveler
information systems as well as traffic management actions including
variable messages and route guidance. The development of the DYNASMART-X
system entails cutting-edge methodological development in the areas
of real-time origin-destination estimation and prediction, fast
and efficient optimum path search algorithms for networks with time-dependent
travel times and costs, real-time traffic flow modeling and simulation,
multi-class dynamic network assignment algorithms, consistency checking
and updating logic, as well as distributed traffic system simulation
and management software. In addition to methodological development
and working prototype implementation, this study conducted calibration
and validation testing using the network of Irvine, CA. Additional
information can be found at the DYNASMART web site.
Researcher: Hani S. Mahmassani
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A State-of-the-Art Dynamic Network
Traffic Operational Planning Tool. DYNASMART-P is
a state-of-the-art dynamic network traffic operational planning
tool, developed and supported at the University of Maryland under
the FHWA’s Dynamic Traffic Assignment (DTA) research project.
DYNASMART-P (DYnamic Network Assignment-Simulation Model for Advanced
Road Telematics) supports transportation network planning and traffic
operations decisions, including evaluation of ITS deployment options,
through the use of simulation-based dynamic traffic assignment.
The methodology combines (1) dynamic network assignment models,
used primarily in conjunction with demand forecasting procedures
for planning applications, and (2) traffic simulation models, used
primarily for traffic operational studies. DYNASMART-P provides
the capability to model the evolution of traffic flows in a traffic
network, which result from the decisions of individual travelers
seeking the best paths en-route over a given planning horizon. It
overcomes many of the known limitations of static tools used in
planning practice. Such limitations pertain to the types of alternative
measures that may be represented and evaluated, and the policy questions
that planning agencies are increasingly asked to address.
DYNASMART-P defines a new generation of transportation planning
methodologies, which can interface with existing four step procedures,
yet provides a meaningful jump in the range and type of measures
that can be evaluated. Because it considers the time-varying nature
of traffic flows, it is expected to produce more useful estimates
of network conditions such as speeds, queue lengths, delays, and
congestion effects to better assess the functional and environmental
impacts of a variety of traditional and emerging transportation
planning measures, including the deployment of ITS and non-ITS technologies.
As such, DYNASMART-P serves an important role in bridging the traditional
gap between planning methods and traffic operations. Additional
information can be found at the DYNASMART web site.
Researcher: Hani S. Mahmassani
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Application and Testing of DYNASMART-X
Real-Time DTA System for the Maryland CHART Traffic Management Center.
This study, in collaboration with the Maryland State Highway Administration,
is intended to illustrate the application of a state-of-the-art
real-time dynamic traffic assignment system to estimate and predict
traffic network conditions and travel times along the I-95 corridor
between the northern DC area (from the north Beltway) to the southern
edge of Baltimore. This network is covered by detectors and surveillance
cameras controlled through the CHART statewide traffic management
center. The objective of the study is to test the ability of the
DYNASMART-X to operate in real-time on a large regional network,
and interface with actual sensor data. In addition, an objective
of the study is to examine the sensitivity of the solution quality
to the extent of detector coverage, and to demonstrate its utility
to support traffic management decisions under incident conditions
and other disruptions.
Researchers: Hani S. Mahmassani, Phillip Tarnoff
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Online
Transportation Markets: Performance Models and Real-Time Fleet Operational
Strategies.
Online markets for transportation services, in the form of Internet
sites that dynamically match shipments (shippers’ demand)
and transportation capacity (carriers’ offer) through auction
mechanisms are changing the traditional structure of transportation
markets. Beyond changes in market structure, Internet auctions have
emerged as an effective catalyst to sell/buy through electronic
marketplaces. Transaction time, cost, and effort could be dramatically
reduced, creating new markets and connecting buyers and sellers
in ways that were not previously possible.
Two types of resources could be traded in transportation marketplaces:
(a) loads, or demands of shippers, being "sold" to the
lowest bidder-- this would be the case of extra supply looking for
scarce demands; and (b) capacity, i.e. the capacity to move goods,
by a given mode from location A to location B, being “sold”
to the highest bidder. The buyer of such capacity could be a shipper
wishing to move a load, a carrier needing the extra capacity to
move contracted loads, or a third party hoping to make a profit
by reselling this capacity.
Auction-based electronic marketplaces give rise to new dimensions
in the behavior of the principal freight transportation decision
agents, especially with regard to learning and adaptation in a competitive
bidding environment. Behavioral considerations play a critical role
in determining the performance of auction-based electronic freight
markets, and the policy implications of different marketplace rules
and regulatory requirements. This study, funded by the National
Science Foundation, is developing a theoretical and methodological
framework for the analysis of spot markets for truckload trucking
service acquisition, as well as bidding strategies under different
informational situations and market designs. A major focus of the
study are the implications for market structure and the economic
impact on shippers.
Researchers: Hani S. Mahmassani, in collaboration
with Dr. Patrick Jaillet (MIT).
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Econometric
Analysis of the Effectiveness of Generic Dairy Advertising, funded
by the National Dairy Board.
Dr. Gabriel and Dr. Bozdogan (and others) analyzed the effectiveness
of advertising for generic dairy products (milk, cheese, etc.).
Their research was based on using a variety of statistical techniques
such as regression with special time series and cross-sectional
considerations. Their work was made part of a report to the U.S.
Congress.
Researcher: Steven Gabriel
1984-1986
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Methodology
and Guidelines for Risk-Informed Analysis for the Engine Room Arrangement
Model, funded by the Naval Surface Warfare Center, Carderock Division.
In this report, a methodology and guidelines for using reliability
and risk analysis methods for the Engine Room Arrangement Model
(ERAM) of the U. S. Navy were developed and illustrated. The methodology
is called the Engineered Marine System Assessment (EMSA) methodology.
Reliability and risk computations were performed using fault- and
event-tree commercial computer programs that were examined and evaluated
for this purpose. Also, web-based computational programs were developed
that can be accessed from the web site of the Center for Technology
and Systems Management (CTSM) at the University of Maryland, i.e.,
http://ctsm.umde.edu. The suggested methodology can be used to assess
and analyze different systems aboard naval and merchant vessels.
The guidelines can provide Navy engineers with the needed tools
for performing risk-informed assessments of marine systems such
as ERAM systems.
Reliability assessment programs with a user friendly, web interface
were developed to support the EMSA methodology. The computational
procedures for the different methods were developed in a modular
form. The resulting programs are called Web-based STructurAl Reliability
assessment (WSTAR) consisting of the following 4 modules: Advanced
Second Moment (ASM), Monte Carlo simulation (MC), Conditional Expectation
(CE), Time-Dependent Reliability (TDR), and Fault Tree Analysis
(FTA). The significance of the software development procedure in
this study is in establishing prototype reliability assessment software
that can be accessed and used on the World Wide Web.
Research: Center for Technology and Systems Management
Bilal M. Ayyub, Director (with Ibrahim Assakkaf, Clara Popescu,
Zbigniew Karaszewski)
1998-2000
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The
Interactive Effects of Telecommunications and Transportation on
Residential Location Flexibility and Choice. Funded by New England
University Transportation Center, funded by the US Department of
Transportation.
As information and communications technologies (ICT) are becoming
essential means of spatial interaction for an increasingly large
percentage of the world's population, today, more than ever, telecommunications
has major implications for travel demand and housing choice. This
research has two objectives: (1) to expand and improve an analytical
framework for understanding how telecommunications may affect individuals'
location choice in contemporary metropolitan areas, and (2) to apply
the resulting analytical tool to an exploration of possible future
changes in urban spatial structure. Its methodological approach
is distinguished by the development of an economic measure of spatial
impedance that accounts for both the time savings and the monetary
expenses associated with remote interaction via ICT.
Researcher: Qing Shen
1999-2002
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Transit
Mobility, Job Access, and Low-Income Labor Participation in U.S.
Metropolitan Areas, funded by the National Science Foundation.
This study tests the hypothesis that improved transit mobility can
effectively reduce unemployment by linking unemployed and car-less
persons with appropriate jobs. Specifically, it examines whether
increased transit access is associated with the case status (employment
status) of Temporary Assistance for Needy Families (TANF) recipients
in the Atlanta, Baltimore, Dallas, Denver, Milwaukee, and Portland
metropolitan areas. Individual TANF recipient location data, transit
route/stop data, and employment location data are used in limited
dependent variable regression analyses to predict the employment
status of TANF recipients in the six selected metropolitan areas.
Researcher: Qing Shen (with Thomas Sanchez of Virginia
Tech and Zhongren Peng of University of Wisconsin at Milwaukee)
2000-2002
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Application
of fiber reinforced polymer (FRP) on bridge deck, funded by the
Federal Highway Administration, Innovative Bridge Research &
Construction program assigned to the Maryland State Highway Administration.
Use of FRP-composite bridge decks is viewed as a potential long-term
solution for the concrete deck deterioration problem. Other incentives
for using FRP-composite materials include the material's inherent
high strength-to-weight ratio. Use of composite structural deck
surfaces can decrease the "dead load" associated with the bridge
and therefore increase vehicle-load-carrying capabilities of the
bridge.
Researcher: Chung C. Fu
2000-2002
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Assessment
of the Construction Feasibility of the Mobile Offshore Base Special
Topics, funded by the Office of Naval Research and Naval Facilities
Engineering Service Center.
The Office of Naval Research (ONR) has established a science and
technology program to explore the concept of a prepositioned floating
military base called the Mobile Offshore Base (MOB). A MOB is a
large platform up to 1500m (1 mile) in length by 120m (400 feet)
in width that would be moved for long-term deployments in support
of national defense priorities. The platform would be unprecedented
in size and operations compared to any floating structure built
to date. Operational requirements for the MOB include the ability
to support Air Force cargo aircraft, support container ships, provide
massive storage of bulk and liquid stores, house 10,000 or more
troops, and discharge various amphibious craft.
The primary objective of the ONR science and technology program
is to determine technical feasibility and cost of a MOB. As part
of this ONR program, the Center for Technology and Systems Management,
Department of Civil Engineering at the University of Maryland College
Park developed an assessment of the construction feasibility for
five proposed MOB concepts.
Research: Center for Technology and Systems Management
Bilal M. Ayyub, Director (with William J. Bender, Andrew Nyakaana
Blair).
2000-2002
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Load
and Resistance Factor Design (LRFD) Rules as Performance-Based Design
Criteria for Surface Ships, funded by the Gulf Coast Region Maritime
Technology Center.
The objective of the study is to develop load and resistance factor
design (LRFD) rules for ships. The outcomes of the project are design
models and equations, and partial safety factors that can be used
to compose LRFD rules and criteria. The LRFD rules and criteria
can initially be used in parallel with currently used procedures,
with the ultimate goal of phasing out the currently used procedures.
The first year of this study resulted in design models and equations,
and partial safety factors that can be used to compose LRFD rules
and criteria for hull girder bending of surface ship structures
that builds on previous work and accounts for both longitudinal
and transverse bending for both commercial and naval vessels. The
second year of the same study also resulted in design models and
equations for unstiffened, stiffened, and gross panels of ship structures.
It also provided partial safety factors for use in LRFD rules and
criteria for panels used in both commercial and naval ships. The
third year (current year) includes development of LRFD criteria
for fatigue of surface ship structures. Results from ongoing Ship
Structures Committee studies were considered and incorporated in
the report as they relate to the tasks of the project.
The report surveys available strength models, fatigue details, and
methods for assessing and evaluating load effects. Statistical characteristics
of strength and load variables, and design methods are summarized.
LRFD-based partial safety factors are provided for the design and
analyses of various structural components of a surface ship. Reliability-based
fatigue design and crack control methods are proposed and illustrated
in the report. Also a bibliography is provided.
Research: Center for Technology and Systems Management
Bilal M. Ayyub, Director (with Ibrahim A. Assakkaf, Norma Jean Mattei
of the University of New Orleans).
2000-2002
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Knowledge-based
Bridge Management Decision Support, funded by the Dwight David Eisenhower
Transportation Fellowship National Highway Institute of Federal
Highway Administration.
The main purpose of this study is to develop a model to represent
and evaluate the failure cost of bridge elements using a knowledge-based
system and also develop a methodology to populate the failure cost
model with real data (Maryland data) The project was sponsored and
assisted by both the FHWA and MDSHA.
Researcher: Chung C. Fu
2000-2001
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Software
Development and Research for the Sign Bridge Program (SABRE), funded
by the MD State Highway Administration.
Design and erection of highway sign supports has been made easier
by development of a dedicated computer program, WIN-SABRE, a Sign
Bridge Analysis and Evaluation System. The program contains many
special features. With these special features, it is now possible
to design and analyze a fairly complicated sign bridge structure
in minutes rather than hours, resulting in a significant increase
in productivity. The program also serves as an evaluation tool in
sign structure Management Systems.
Researcher: Chung C. Fu
2000-2001
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Decision
Making Software Development to Damaged Pole, funded by the MD State
Highway Administration.
OMT (Office of Materials and Technology) metals technicians and
OOTS (Office of Traffic and Safety) signal technicians of the Maryland
State Highway Administration are frequently requested to investigate
the damage to signal/light poles and sign structures resulting from
traffic accidents. Often the circular steel tube uprights of the
poles/structures have been dented. This permanent deformation varies
in size and generally does not visually affect the upright. When
there is no tearing of the metal at the deformation it is difficult
to determine if the structural integrity of the upright. When there
is no tearing of the metal at the deformation it is difficult to
determine if the structural integrity of the upright has been compromised.
That evaluation is compounded by the type of loading on the structure
and its relationship to the deformation.
Researcher: Chung C. Fu
2000-2001
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Maryland
Study, Vehicle Collisions with Highway Bridges, MD State Highway
Administration.
Numerous studies have examined the effects of large vehicles on
bridge structures; however, most have focused on vehicle weights
and not on heights. Bridges over highways are designed to provide
a specified minimum vertical clearance. Many commercial vehicles
exceed these clearances. Regulations are in place to route these
overheight trucks around low bridges, but they are not always followed.
Overheight vehicles often collide with bridge superstructures, causing
structural damage, injuries, and sometimes even fatalities. For
example, in 1999 an excavator on a flatbed trailer struck and collapsed
a pedestrian bridge over the Baltimore Beltway, killing one motorist
and injuring three others. This study was initiated to assess the
magnitude of overheight vehicle collisions and to identify potential
countermeasures, if warranted.
Researcher: Chung C. Fu
2000-2001
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Experimental
Plan for Calibration and Validation of Hot Mix Asphalt Performance
Models for Mix and Structural Design, funded by the National Cooperative
Highway Research Program, National Research Council.
In NCHRP Project 1-37A, "Development of the 2002 Guide for the Design
of New and Rehabilitated Pavement Structures", an analytical approach
is used for the calibration and validation of the HMA models; the
calibration and validation are based on material properties either
contained already in the LTPP database or derived from LTPP data
by calculation. NCHRP Project 9-30 will develop an experimental
plan to refine this calibration and validation using material properties
measured with the requisite test methods on laboratory-prepared
HMA specimens or field cores where necessary. Contingent on future
funding, projects are planned to (1) carry out this experimental
plan beginning about January 2003 and (2) incorporate the refined
models in the 2005 mix design guide.
The objective of this research is to develop a detailed, statistically
sound, and practical experimental plan to refine the calibration
and validation of the performance models incorporated in the proposed
2002 design guide with laboratory-measured hot mix asphalt (HMA)
material properties for future use in mix and structural design
methods.
Researcher: Charles W. Schwartz, Co-Principal Investigator
(with H.L. Von Quintus, of Fugro-BRE).
October 2001 - February 2003
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