Emissions Reduction Through Better Traffic Management
H. C. Frey and N. M. Rouphail
NC Department of Transportation
4/99 to 6/01
The objectives of this research are: (1) assemble, evaluate, and validate
a new low-cost on-board emissions measurement (OBEM) system; (2) investigate
factors that affect the level and variability of on-road emissions using rigorous
statistical methods; and (3) devise methods for designing and conducting experiments
that realistically evaluate vehicle-based pollution prevention strategies.
The relationship between traffic signalization and vehicle emissions for selected
traffic corridors will be evaluated as an illustrative testbed for our general
approach. The key expected results are demonstration of: (a) a new
low-cost approach for OBEM and (b) a new method for evaluation of the pollution
prevention impacts of traffic management strategies using the OBEM approach.
Evaluation of Safety, Design, and Operation of Shared Use Paths
J. E. Hummer, N. M. Rouphail, and J. S. Milazzo II
Federal Highway Administration
10/00 to 9/03
Off-street paths used by pedestrians, bicyclists, and other non-motorized users
are becoming common in the U.S. The purpose of the project is to develop
and validate a quantitative procedure for estimating the quality of service
offered by paths of different widths and configurations handling different volumes
of users. A major work element in this research is the collection of operational
data on paths across the U.S. The research team will also collect an extensive
database of path user perceptions. Another important part of the research
is the development of a plan to communicate the quality of service procedure
to designers and operators across the U.S.
Guidance on the Safe Implementation of Unconventional Arterial Designs
J. E. Hummer
Southeastern Transportation Center
8/00 to 7/01
Unconventional arterial designs like median u-turns, superstreets, and continuous
flow intersections have the potential to significantly reduce delay compared
to conventional arterial designs of similar size. However, designers avoid
these new designs because they are concerned that drivers will not understand
how to negotiate them when first introduced. The purpose of the project
is to explore this concern and highlight ways in which it can be alleviated.
The research team is 1) examining case studies from the southeast and elsewhere
where agencies opened new designs; 2) looking at traffic control devices, enforcement
levels, and public relations tools used by those agencies; and 3) gathering
detailed reactions to those devices and tools from a focus group of typical
drivers.
Highway Safety Related to Traffic Control Devices
J. E. Hummer
3M Company
5/00 to 12/00
This unrestricted grant supported my research in highway safety and traffic
control. I developed ideas, wrote proposals, and added to the scope of
my study on traffic control for unconventional arterial designs (described in
J. E. Hummer abstract, “Guidance on the Safe Implementation of Unconventional
Arterial Designs”).
Phase IV Planning Assistance and Support Services to the NCDOT Rail Division
J. E. Hummer
NC Department of Transportation (NCDOT)
8/00 to 12/01
To overcome some of the problems with traditional active warning devices at
railroad grade crossings, the EVA Signal Corporation has developed a new, relatively
low-cost system. As part of a team assembled by the Institute of Transportation
Research and Education, we will evaluate the new system at an installation in
Rich Square, NC. We will test the reliability of the system and assess
driver responses to the new types of signals using motorist surveys, field observations,
and video recordings.
Reducing Aggressive Driving in North Carolina with Education, Engineering,
and Enforcement
J. S. Milazzo II and J. E. Hummer
NC Governor’s Highway Safety Program
7/99 to 9/00
The major objective of this project is to identify practical means of reducing
collisions related to aggressive driving. We are comparing the collision
records of drivers observed performing various aggressive maneuvers with collision
records of unaggressive drivers. The aggressive maneuvers that are cost-effective
to combat with some countermeasure and that are most closely related to high
collision frequencies will be recommended for attention.
State Farm Insurance Program—Intersection Safety Study
J. E. Hummer
City of Charlotte, NC
9/00 to 8/01
State Farm Mutual Automobile Insurance Company recently began an effort to stem
the tide of collisions at some of the most hazardous intersections in the U.S.
and make the public aware of the frequency of crashes at these locations.
In one component of the program, State Farm has offered the responsible highway
agencies up to $20,000 per intersection to study these sites and produce countermeasure
recommendations. Four of the five most hazardous intersections in North
Carolina as identified by State Farm are in Charlotte, and three of these will
be the subjects of this study. Our particular focus will be on examining
potential unconventional design solutions at those intersections.
Traffic Signal Enforcement Innovations for North Carolina
J. E. Hummer and J. S. Milazzo II
NC Governor’s Highway Safety Program
10/98 to 9/00
Through a literature review, professional contacts, focus groups, and an analysis
of data collected at current installations, we are analyzing the effectiveness
of automatic red light running enforcement through video cameras. We are
then predicting where, and under what conditions, more cameras would improve
safety in North Carolina cities. We are also investigating the effectiveness
of various types of public information campaigns in conjunction with camera
installation.
Acquisition of Constructed Infrastructure Testing System
D. W. Johnston, S. H. Ahmad, N. P. Khosla, R. H. Borden, and L. E. Bernold
National Science Foundation and NC State University
1/95 to 12/00
The nation's constructed infrastructure has accumulated a large backlog of needs.
Anticipating the increased national awareness of the deteriorated state of the
nation's constructed infrastructure, the Civil Engineering faculty has developed
the Constructed Facilities Laboratory (CFL) as a part of the new Engineering
Graduate Research Center at NC State. The CFL contains integrated spaces
for research/development in Performance of Large Structural Systems, Fabrication
and Characterization of Cementitious Composites, Evaluation of Construction
Systems, and Geotechnical Techniques and Soil Improvement. This grant
allowed the faculty investigators to acquire state-of-the-art testing equipment
for critical constructed infrastructure research and assessment.
Evaluation of the Effects of Mixture Properties and Compaction Methods on the
Predicted Performance of Superpave Mixtures
N. P. Khosla
NC Department of Transportation/Federal Highway Administration
7/00 to 6/02
The objectives are 1) evaluate the effects of compaction type on a mixture’s
performance as measured by the APA, Wheel Tracking Device at NCSU, and Repeated
Shear Constant Height Test; 2) evaluate how changes in aggregate and asphalt
source affect mixture compaction and predicted performance in the test systems
listed above using several SUPERPAVETM mixtures from different field sites in
NC; 3) compare the predicted performance of test samples compacted in the field
to the same mixtures compacted using the laboratory compaction systems listed
above; 4) evaluate and compare the field densification of mixtures with varying
degree of compaction in the SUPERPAVETM gyratory compactor; and 5) evaluate
the frictional resistance of mixtures as measured by the new load cell plate
technology for the SGC and compare to the results of the other performance prediction
equipment.
Performance Evaluation of Fine Graded Superpave Mixtures for Surface Courses
N. P. Khosla
NC Department of Transportation (NCDOT)/Federal Highway Administration
7/99 to 6/01
The specific objectives of this research are: 1) study the aggregate gradation
curves and investigate the use of natural sand in the fine and coarse gradations
for the Surface Course mixtures; 2) design the mixtures using the SUPERPAVETM
mix design approach and conduct testing of the selected asphalt mixtures, including
the SUPERPAVETM performance tests to evaluate their performance in terms of
resistance to rutting, fatigue, and moisture damage; 3) compare the accelerated
performance test results of the selected asphalt mixtures using the NC State
University Wheel Track System and the NCDOT Asphalt Pavement Analyzer (APA);
and 4) evaluate if these mixes are economical to be produced and recommend the
guidelines for designing and producing fine graded asphalt mixtures.
A Unified Approach to Predicting Long Term Performance of Asphalt-Aggregate
Mixtures
Y. R. Kim, R. H. Borden, and Y. Horie
National Science Foundation
9/98 to 8/01
The research objective is to develop test methods and models for predicting
long term performance of asphalt concrete that can account for viscoelasticity,
damage, volumetric/deviatoric coupling, temperature, and aging. The objective
will be accomplished by applying the elastic-viscoelastic correspondence principle
and the continuum damage theory. The constitutive model will be incorporated
into the ABAQUS finite element code and used to predict the response and performance
of laboratory pavements loaded by the Model Mobile Load Simulator. Nondestructive
surface wave tests will be performed to determine the change in material properties
due to fatigue damage growth.
Development of Specification Testing to Promote Fracture Fatigue Resistance
and to Optimize Microdamage Healing
Y. R. Kim and M. N. Guddati
Texas A&M Research Foundation/Western Research Institute/Federal Highway
Administration
7/99 to 6/03
The ultimate goal of this project is “to be able to classify/specify/improve
asphalts by their healing rates and efficiencies using chemical data that can
be acquired more rapidly than by mechanical methods.” To accomplish this
goal, the viscoelastic, continuum damage model developed by the PI will be tied
to the micromechanical properties of component materials using microscopic lattice
modeling. Various test methods will be explored for binder specification
testing using the viscoelastic, continuum damage formulation and micromechanical
simulation with an objective to promote fatigue resistance and to optimize the
microdamage healing potential.
Development of Visco-Elasto-Plastic Continuum Damage Model for Asphalt-Aggregate
Mixtures
Y. R. Kim
Arizona State University
3/00 to 12/01
This project is a subcontract from Arizona State University as a part of the
NCHRP 9-19 project “Superpave Support and Performance Models Management.” The
objective of this project is to develop test protocols and models for characterization
of asphalt concrete that are needed for structural design and mix design.
The NC State University research team will perform experimental/analytical research
to evaluate elastic, viscoelastic, and viscoplastic responses of asphalt concrete
under varying conditions and to develop a constitutive model that can be implemented
in finite element analysis for performance prediction of asphalt pavements.
Fatigue Performance Evaluation of WesTrack and Arizona SPS-9 Asphalt Mixtures
Using Viscoelastic Continuum Damage Approach
Y. R. Kim
Federal Highway Administration/NC Department of Transportation
7/98 to 6/00
The principal objectives of this research are: (1) to investigate causes
for early fatigue failure of WesTrack and Arizona SPS-9 pavements using the
viscoelastic continuum damage fatigue model, (2) to evaluate the effects of
mix variables (e.g., asphalt content, air voids content, aggregate gradation)
and testing conditions (e.g., temperature, confining pressure, and moisture)
on fatigue performance of asphalt concrete using the fatigue model, (3) to verify
the fatigue performance prediction using actual performance data from the experimental
pavement sections, and (4) to evaluate the viscoelastic continuum damage fatigue
models with different levels of simplification under varying mix and testing
conditions.
Numerical Modeling of Pavement Materials and Structures Using Finite Element
and Discrete Element Methods
Y. R. Kim
North Carolina Supercomputing Center (NCSC)
11/99 to 10/00
This project utilizes the high-level computing in NCSC for simulating the behavior
of asphalt concrete materials and pavements. ABAQUS finite element program
is used to compute responses in various pavement structures subjected to FWD
loads using dynamic analysis and nonlinear material models. The data will
be used to train artificial neural networks that will be used as an inversion
method. Also, the viscoelastic discrete element code will be run at NCSC
to simulate the evolution of fatigue cracking under cyclic loading. This
code will be used to estimate the fatigue cracking resistance of asphalt concrete
based on component material properties.
Use of FWD Multi-Load Data for Pavement Strength Estimation
Y. R. Kim
NC Department of Transportation
7/99 to 6/01
The objective of this research is to develop analysis tools for the evaluation
of multi-load level deflection data to obtain improved or additional information
about the strength and/or remaining life of asphalt concrete pavements.
This objective will be accomplished by adopting nonlinear, dynamic finite element
analysis of asphalt pavements as a means of developing a synthetic database
composed of pavement properties and responses from which various models can
be developed. These models will be verified/calibrated using multi-load
level deflection data measured from pavements located in three different climatic
regions in N.C.
Advanced Rural Transportation Systems: Where Do We Start? How Far
Should We Go?
A. M. Nalevanko, Institute for Transportation Research and Education (ITRE)
and J. R. Stone, Project Team Member, Department of Civil Engineering
Transportation Research Board Transit Cooperative Research Program Project B-17
3/98 to 8/00
Project team members represent ITRE, the Department of Civil Engineering at
NC State University, TransCore, and the KFH Group. The team examined rural
transit operations in order to quantify the costs and benefits of using advanced
technology, and they developed guidelines for matching technologies to local
transit problems.
Operating Policies for Improved Transit Productivity
J. R. Stone and J. W. Baugh
SYSTAN, Inc.
5/00 to 7/01
The purpose of this research is to develop approaches for paratransit operators
who wish to improve system productivity by implementing innovative operating
policies. Using a multiobjective optimization procedure based on simulated
annealing that was developed in the WSTA Mobility Management project, we will
evaluate policy issues in two cities: Santa Clara and Winston-Salem. By
simulating operating policies, we can estimate impacts on vehicle productivity
and on operating costs. The results of the research will be used to establish
general policy guidelines for paratransit routing and scheduling.
The Effects of Roundabouts on Pedestrian Safety
J. R. Stone
University of Tennessee Southeastern Transportation Center (USDOT University
Transportation Center)
8/00 to 8/01
Roundabouts have proven their effectiveness at improving vehicle safety at intersections.
However, U.S. professionals debate their effectiveness for pedestrians.
This research will examine available pedestrian safety data with appropriate
statistical and case study methods to provide additional information on pedestrian
safety at roundabouts.
Transit Customer Satisfaction with Real-Time Information
J. R. Stone
Winston-Salem Transit Authority
7/00 to 12/01
New technology including automated scheduling and vehicle location, digital
communications, interactive telephone service, and dynamic variable message
signs permit real-time bus locations and estimated arrival times to be communicated
to passengers. This research will examine the effects of selected technologies
on transit customer satisfaction and transit system performance.
Trip Generation/Lifecycle Relationship
J. R. Stone
North Carolina Department of Transportation (NCDOT)
7/00 to 6/01
Current NCDOT trip estimation models rely on costly, subjective estimates of
household condition observed during field surveys. In this research NC
State University and the National Institute of Statistical Sciences will examine
the relationship between household condition and easily acquired property tax
data in Geographic Information System (GIS) format. If a strong relationship
exists, we will propose a new trip estimation method that is easier and less
expensive than current methods.
A Mechanistic Approach to Evaluate Contribution of Prime and Tack Coats in
Composite Asphalt Concrete Pavements
A. A. Tayebali and S. Rahman
NC Department of Transportation (NCDOT)
7/00 to 6/02
The importance of proper AC layer interface bonding cannot be overemphasized
for good performance of AC pavements. A strong bonding between layers
is critical to dissipate shear stresses into the entire pavement structure.
On the other hand, lack of bonding may cause slippage phenomenon and activate
distress mechanisms that will rapidly lead to total failure of the pavement.
The objective of this study is to evaluate the effects of different prime and
tack coats on the bond strength in relation to the thickness of the asphalt
concrete layer. In particular, the distribution and dissipation of shear
stresses under traffic loading and how they affect the interlayer bonding will
be studied. Based on the results of the study, correlation will be developed
between delamination parameters and stress-strain-displacement field.
Materials Characterization and Performance Properties of Superpave Mixtures
A. A. Tayebali
NC Department of Transportation (NCDOT)
1/01 to 12/02
A critical step in the implementation of mechanistic/empirical design procedure
is the development of strain-fatigue life relationship. In this investigation,
materials characteristics and fatigue performance of few asphalt mixes currently
used in North Carolina will be evaluated. The study of these mixes will
initiate the development of a better understanding of the capacity of Superpave
mixes to resist fatigue distress by providing information that can be used to
identify deficiencies and make necessary improvements in the current NCDOT design
procedures.
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