Transportation
Systems and Materials
Research Project Abstracts: 2003
- 2004
Photo Enforcement/Speed Camera
J.E. Hummer
NC Governor's Highway Safety Program
10/03 to 09/04
Speed enforcement cameras that automatically record the license number of a
vehicle exceeding a limit are one technologically-feasible way to address speed-related
safety problems. The North Carolina Legislature has recently given the City
of Charlotte approval to use speed enforcement cameras. The purpose of this
project is to help evaluate those installations, to see whether other highway
agencies could expect collision reductions should they also use speed enforcement
cameras. The project will consist of a literature review, an examination of
public opinion through focus groups, and before-and-after collision and speed
studies at camera sites.
Expanding the Use of Photo Enforcement to Enhance Traffic Safety in North
Carolina, Year 2
J.E. Hummer
NC Governor's Highway Safety Program
10/03 to 09/04
One of the primary causes of crashes at intersections across the state of North
Carolina and across the United States is when a vehicle enters an intersection
during the red interval. Red light camera photographic enforcement has been
used in the United States since 1992, and has been used in North Carolina in
the past five years, to try to address those crashes. However, to this point
there has not been valid research completed to prove their safety benefits.
In this project, we will conduct a before-and-after test with comparison sites
in Raleigh, NC to examine those safety benefits.
Developing Planning Level Crash Prediction Models
J.E. Hummer
University of Tennessee
10/03 to 08/04
The main objective of the project is to develop models that predict the future
number of reported crashes on one or more major types of roadway using only
average daily traffic and other simple inputs typically available during long-range
transportation planning. Planners can then use the models to help prioritize
future roadway improvement projects, when typically now only very crude collision
rates are used in an ad hoc way for such purposes.
False Capacity for Lane Drops
J.E. Hummer and N.M. Rouphail
NC Department of Transportation
07/01/02 to 12/31/03
The purpose of this research is to use a set of field-verified estimates for
the lane utilization factor at a signalized intersection when there is a downstream
lane drop and to estimate collision rates for lane drop areas around signalized
intersections, including lane drops at the intersection. This will be achieved
by the collection of data on two-lane-to-one and three lane-to-two lane drops,
but not other configurations. The researchers will consider dual left turn lanes
with downstream lane drops-those that terminate on surface streets and interchange
ramps-as well as through lanes. All data collection during the project will
be in North Carolina.
Reasonable Speeds on Improved Curb and Gutter Facilities
J.E. Hummer and B.M. Williams
North Carolina Department of Transportation
07/03 to 12/04
Agencies often construct vertical curbs on new multilane highways which usually
necessitates 45 mph speed limits. This may create an enforcement problem, as
drivers do not perceive danger from the curbs. The purpose of this research
is to show agencies how to avoid this scenario by answering two key questions.
First, do vertical curves next to high-speed lanes really cause more frequent
and severe collisions than other cross-section choices? Second, if vertical
curbs are more dangerous, is a lower speed limit the best way to alert the public
to this danger or are there other treatments?
Development of Specification Testing to Promote Fracture Fatigue Resistance
and to Optimize Microdamage Healing
Y.R. Kim and M.N. Guddati
FHWA/WRI/Texas A&M Research Foundation
07/99 to 12/03
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 micro-mechanical properties of component materials using DM2,
a discrete element code developed by the Co-PI. Various test methods will be
explored for binder specification testing using the viscoelastic, continuum
damage formulation and DM2 simulation with an objective to promote fatigue resistance
and to optimize the microdamage healing potential.
Characterization of ALF Mixtures Using the Viscoelastoplastic Continuum
Damage Model
Y.R. Kim and M.N. Guddati
Federal Highway Administration
08/15/03 to 08/14/05
The primary objectives of the proposed research are: (1) to verify the time-temperature
superposition principle in damaged states for various asphalt mixtures used
in the current ALF study; (2) to characterize the ALF mixtures using the viscoelastoplastic
continuum damage model; and (3) to predict the performance of various ALF pavements
using finite element analysis and the VEPCD model.
Optimizing Gradations for Surface Treatments
Y.R. Kim
NC Department of Transportation
07/01/03 to 06/30/05
Due to the ongoing commitment to pavement preservation and the growing number
of miles of low volume roads, the use of surface treatments has increased substantially
in recent years. This increase in the use of surface treatments has led state
agencies to invest in reviewing their design procedures and to modify their
existing specifications and develop new mix design systems. The primary objective
of this proposed research project is to evaluate the current mixture characteristics
of surface treatments used in North Carolina and recommend modifications to
the current specifications, particularly those related to aggregate gradations.
Determination of Dynamic Moduli for Typical North Carolina Asphalt Mixtures
Modified with Lime
Y.R. Kim
Chemical Lime Company
05/03 to 05/04
The objective of this proposal is to develop a dynamic modulus database for
typical asphalt mixtures modified with lime in parallel with the NCDOT database.
Only the axial compression test method will be used in this project with the
anticipation of adding the indirect tension test method later when funds are
avaiable. Also, the applicability of Witczak's predictive equation to lime-modified
mixtures will be evaluated. The dynamic modulus database to be developed from
this project will yield necessary information for the NCDOT to design asphalt
pavements with lime-modified mixtures using the new AASHTO pavement design guide.
Typical Dynamic Moduli for North Carolina Asphalt Concrete Mixes
Y.R. Kim
NC Department of Transportation
07/01/02 to 06/30/04
The dynamic modulus of asphalt concrete will be used as the key parameter in
the 2002 AASHTO Design Guide as well as in the Superpave simple performance
test protocol that complements the volumetric mix design. The release of the
new AASHTO pavement design guide in 2002 makes it urgent to obtain dynamic moduli
values of typical asphalt mixes used in North Carolina. The objective of this
proposal is to develop a database of dynamic moduli values and their variability
for asphalt mixes used in North Carolina. In addition to dynamic modulus testing
of the representative mixes, surrogate methods will be evaluated, including
the impact resonance method and Witczak's predictive equation.
Impact of Price Reductions on the Long-Term Pavement Performance of HMA
Mixes in North Carolina
Y.R. Kim
NC Department of Transportation
07/01/01 to 06/30/03
Article 105-3 of the North Carolina Department of Transportation (NCDOT) Standard
Specifications for Road and Structures provides guidance on price adjustments
for hot mix asphalt pavements that are not within reasonably close conformity
with the specifications but for which the work is to be accepted and remain
in place. The primary objective of the proposed research herein is to determine
whether price reduction under the provisions of Article 105-3 is adequate. The
research objective will be accomplished by conducting both field and laboratory
analyses of deficient pavements and specification pavements with similar structures
and traffic history. The types of deficiency to be addressed in this research
include asphalt content and in-situ density. Both fatigue and rutting performance
will be evaluated.
Multi-Modal Arterial Level of Service
Richard Dowling (PI: Nagui M. Rouphail)
NCHRP 3-70
03/01/03 to 06/30/04
The objective of this research is to develop and test a framework and enhanced
methods for determining levels of service for automobile, transit, bicycle,
and pedestrian modes on urban streets, in particular with respect for the interaction
among the modes.
In-Vehicle Energy and Emissions Information System
H. Christopher Frey and Nagui M. Rouphail
National Science Foundation
01/03 to 12/05
The key objectives of this research project are to: (1) develop a micro-scale
predictor of energy use and emissions that is deployable at the individual vehicle
level in real-time; (2) identify, compare and evaluate alternate energy use
and emissions sampling/reporting schemes that are appropriate at the vehicle
and network levels; (3) Develop and test a prototype In-Vehicle Energy and Emissions
Information System (IVEEIS); and (4) formulate and assess the utility of IVEEIS
in developing transportation design and control measures aimed at energy and
emission management policies.
Operational Evaluation of Emissions and Fuel Use of B20 vs. Diesel Vehicles
H. Christopher Frey and N. M. Rouphail
North Carolina Department of Transportation
10/03 to 09/04
This project involves design and implementation of a field data collection study
on diesel vehicles to measure second-by-second emissions of NOx, Particulate
Matter, CO, and CO2, fuel use, engine data, and vehicle activity (e.g., speed,
location) data using an on-board portable instrument. Benchmark modal emission
rates will enable comparison of B20 and conventional diesel fuel, estimation
of emission factors, and identification of opportunities to reduce emissions
and fuel use through improved vehicle operation. Strategic recommendations will
be made regarding biodiesel fuel, air quality management, energy management,
and improved operation.
Designing and Efficient Nighttime Sign Inspection Program that Ensures Motorist
Safety
W. Rasdorf and J. Hummer
NC Department of Transportation
07/01/04 to 06/30/06
The major objective of the research is to revise and expand out simulation of
the effectiveness of sign inspection programs so that NCDOT can optimize its
program. The main revisions to allow NCDOT to use the simulation are to:
Model the performance of NCDOT sign inspectors,
Expand the simulation to include other sign colors besides yellow and red,
and
Include the best sign deterioration functions.
North Carolina Level of Service (LOS) Program
N. M. Rouphail (Co-PI Robert S. Foyle)
NC Department of Transportation
07/02 to 06/04
The purpose of this research is to provide a consistent method for determining
expected service volumes and capacities for a given set of roadway, geographic,
traffic, or other characteristics to the North Carolina Department of Transportation
Statewide Planning (SWP) Branch. The product will allow for appropriate variation
among geographic, terrain, traffic, and other differences that may affect facility
performance apart from roadway characteristics. This will be determined by examining
existing LOS methodologies and products, establishing which roadway facilities
will be covered, determining critical default values for North Carolina, creating
level-of-service tables and developing software product for SWP and training
SWP staff.
Incident Management and Assistance Patrols: Assessment of Investment Benefits
and Costs
N. M. Rouphail (Co-PI A. J. Khattak)
NC Department of Transportation
07/01/02 to 12/31/03
The purpose of this research is to review patrol benefit-cost literature and
synthesize their findings to explore implications for North Carolina. To develop
criteria to identify IMAP expansion opportunities within NC and to utilize detailed
NC data on traffic demand, capacity, incidents and hypothetical IMAP attributes
(miles patrolled per day, number of IMAP vehicles, number of incident responses
per day and response times) in the "high-impact" areas, along with
a traffic model (FREEVAL) to assess the benefits of IMAPS
Identification of Traffic Control Devices for Mobile and Short Duration
Work Operations
R.E. Paaswell (Subcontract to ITRE Nagui M. Rouphail)
New Jersey, Dept. of Transportation
01/01/04 to 12/31/04
The purpose of this research is to provide improvements for maximum protection
of the motoring public and workers in mobile work zones and in the set up of
work zones, and to identify state-of-the-art work zones technologies to improve
worker safety in mobile work zone and short-term maintenance operations. The
project will identify information systems for work zone traffic control to reduce
delays and crashes, to meet current standards established by internal policies
of the NJDOT and to identify "best practices" for use of law enforcement
to improve work zone safety. Finally key issues will be considered from the
public outreach and information systems perspective.
North Carolina Forecasts for Truck Traffic
J.R. Stone
North Carolina Department of Transportation
07/03 to 12/04
Estimates of truck traffic are critical parameters in designing and maintaining
highway pavement and structures. National databases suggest that trucks are
becoming an increasingly larger proportion of traffic. Anecdotal reports suggest
that North Carolina truck traffic is increasing in excess of national averages.
Consequently designers apply generous adjustments for forecast truck traffic.
However, over estimates lead to over design and unnecessary construction cost.
This project helps resolve these issues through improved data collection, display
and analysis techniques.
Performance Grading (PG) of Iceland Bitumen B-180 and B-85
A. A. Tayebali
Iceland Public Roads Administration
05/15/04 to 08/15/04
The objective of this study is to characterize Asphalts (bitumen) cements B-180
and B-85 used in Iceland, using the Superpave "Performance Grading"
methodology.
Use of Lime as Anti-strip Additive for Mitigating Moisture Susceptibility
of Asphalt Mixes Containing Baghouse Fines
A. A. Tayebali
North Carolina Department of Transportation (NCDOT)
07/01/04 to 06/30/05
The objective of this research project is to conduct a laboratory study of moisture
sensitivity of asphalt mixes containing controlled percentages of Boone and
Enka baghouse fines in the amount of 0, and 4-percent. In this study, lime will
be used as an anti-strip agent to determine its effectiveness in mitigating
moisture damage. The results of this study will complete, and support the outcome
of the previous NCDOT studies that investigated mitigation of moisture susceptibility
of mixes containing baghouse fines with organic anti-strip additives. The recommendations
based on results of this study should enable NCDOT to formulate specifications
with regards to the use of baghouse fines in NCDOT mixes.
Materials Characterization and Performance Properties of Superpave Mixtures
A. A. Tayebali
North Carolina Department of Transportation (NCDOT)
01/01/01 to 12/31/03
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 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.
Quantifying Anti-Strip Additive in Asphalt (Binders and Mixes)
D.R.U. Knappe and A.A. Tayebali
NC Department of Transportation
07/01/03 to 12/31/04
NCDOT requires an antistrip agent in all asphalt mixes. To date, there is no
test procedure to determine the level of organic antistrip agents in asphalt
binders or asphalt mixtures. The objective of this research is to develop a
reliable and repeatable laboratory and/or field test procedure to determine
the amount of organic anti-strip agent in asphalt binders and asphalt mixtures.
In this investigation, two test methodologies will be investigated. These include
1) a colorimetric test, and 2) a litmus test using StripScan device. Both methodologies
utilize a spectrophotometer for the analysis of anti-strip additive concentration
in asphalt mixes.
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
07/01/00 to 12/31/03
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. 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. In particular, the distribution of
shear stresses under traffic loading and how they effect the interlayer bonding
will be studied.
Evaluation of Tack Coat Strength Using Field Device "ATACKER"
A. A. Tayebali
NC Department of Transportation
07/01/03 to 09/30/03
Tack coat is an essential part of overlay and new construction of pavements
in North Carolina. One problem with the use of tack coat, which is an emulsifier,
is the determination of the duration that should be allowed before an additional
layer of asphalt should be rolled on existing asphalt or concrete surface on
which an emulsion tack coat has been applied. The objective of this investigation
is to study the effectiveness of a field device "ATacker" to evaluate
if it can be used to determine when a tack coat is sufficiently broken so that
additional asphalt layer can be rolled on the existing surface.
I-40 Reversal Operational Traffic Analysis
B.M. Williams
North Carolina Department of Transportation
07/03 to 06/05
The NCDOT developed a lane reversal plan for using the eastbound lanes of I-40
for additional hurricane evacuation capacity. Traffic operation under evacuation
conditions, especially operation of reversed lanes, are not well understood.
This project involved investigational research of reverse lane operation and
modeling and analysis of the I-40 lane reversal plan. Results will include recommendations
for improving the current plan.
System-wide Traffic Condition Monitoring and State Estimation for Intelligent
Transportation Systems (CAREER)
B.M. Williams
National Science Foundation
06/02 to 05/07
This five-year research and education program involves the teaching and application
of rigorous and robust statistical modeling techniques to the process of assessing
and predicting traffic stream states based on remotely sensed traffic data in
advanced traffic management systems. Research results will include improved
real-time traveler information, more rapid incident detection and response,
and enhanced information support for dynamic transportation system management.
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