- Tracking Vehicles in Real Time, High Performance Computing, Mass Evacuation, Civil Engineering, Modeling and Simulation, Transportation Engineering, and 11 moreTraffic Simulation, Transport, Heavy Vehicle Safety, Incident Detection, Monte Carlo Simulation, Text Mining, Traffic Engineering, Traffic Signal Control, License Plate Matching, Hurricane Evacuation, Civil & Environmental Engineering, and Ethicsedit
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In traffic operations, the aim of transportation agencies and researchers is typically to reduce congestion and improve safety. To attain these goals, agencies need continuous and accurate information about the traffic situation.... more
In traffic operations, the aim of transportation agencies and researchers is typically to reduce congestion and improve safety. To attain these goals, agencies need continuous and accurate information about the traffic situation. Level-of-Service (LOS) is a beneficial index of traffic operations used to monitor freeways. The Highway Capacity Manual (HCM) provides analytical methods to assess LOS based on traffic density and highway characteristics. Generally, obtaining reliable density data on every road in large networks using traditional fixed location sensors and cameras is expensive and otherwise unrealistic. Traditional intelligent transportation system facilities are typically limited to major urban areas in different states. Crowdsourced data are an emerging, low-cost solution that can potentially improve safety and operations. This study incorporates crowdsourced data provided by Waze to propose an algorithm for LOS assessment on an hourly basis. The proposed algorithm explo...
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Purpose Individuals’ driving behavior data are becoming available widely through Global Positioning System devices and on-board diagnostic systems. The incoming data can be sampled at rates ranging from one Hertz (or even lower) to... more
Purpose Individuals’ driving behavior data are becoming available widely through Global Positioning System devices and on-board diagnostic systems. The incoming data can be sampled at rates ranging from one Hertz (or even lower) to hundreds of Hertz. Failing to capture substantial changes in vehicle movements over time by “undersampling” can cause loss of information and misinterpretations of the data, but “oversampling” can waste storage and processing resources. The purpose of this study is to empirically explore how micro-driving decisions to maintain speed, accelerate or decelerate, can be best captured, without substantial loss of information. Design/methodology/approach This study creates a set of indicators to quantify the magnitude of information loss (MIL). Each indicator is calculated as a percentage to index the extent of information loss (EIL) in different situations. An overall information loss index named EIL is created to combine the MIL indicators. Data from a drivin...
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Knowing tourists’ preferences and experiences with respect to their national park visits is of great importance to implementing strategically sustainable development of national parks. Flickr geotagged photos are utilized and analyzed as... more
Knowing tourists’ preferences and experiences with respect to their national park visits is of great importance to implementing strategically sustainable development of national parks. Flickr geotagged photos are utilized and analyzed as our main data source. We included 7090 photos from 626 people in the Great Smoky Mountains National Park to investigate visitors’ behaviors through the presentations of photo spatial and temporal patterns. The results indicated that tourist behaviors that reflect on what they like and enjoy during their park visits can be extracted from geotagged social media data in terms of frequency and length of enjoyment as visitors’ preferred spots.
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The mechanisms of traffic congestion generation are more than complicated, due to complex geometric road designs and complicated driving behavior at urban expressways in China. We employ a cell transmission model (CTM) to simulate the... more
The mechanisms of traffic congestion generation are more than complicated, due to complex geometric road designs and complicated driving behavior at urban expressways in China. We employ a cell transmission model (CTM) to simulate the traffic flow spatiotemporal evolution process along the expressway, and reveal the characteristics of traffic congestion occurrence and propagation. Here, we apply the variable-length-cell CTM to adapt the complicated road geometry and configuration, and propose the merge section CTM considering drivers’ mandatory lane-changing and other unreasonable behavior at the on-ramp merge section, and propose the diverge section CTM considering queue length end extending the expressway mainline to generate a dynamic bottleneck at the diverge section. In the new improved CTM model, we introduce merge ratio and diverge ratio to describe the effect of driver behavior at the merge and diverge section. We conduct simulations on the real urban expressway in China, wi...
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Freeway travelling time is affected by many factors including traffic volume, adverse weather, accident, traffic control and so on. We employ the multiple source data-mining method to analyze freeway travelling time. We collected toll... more
Freeway travelling time is affected by many factors including traffic volume, adverse weather, accident, traffic control and so on. We employ the multiple source data-mining method to analyze freeway travelling time. We collected toll data, weather data, traffic accident disposal logs and other historical data of freeway G5513 in Hunan province, China. Using Support Vector Machine (SVM), we proposed the travelling time model based on these databases. The new SVM model can simulate the nonlinear relationship between travelling time and those factors. In order to improve the precision of the SVM model, we applied Artificial Fish Swarm algorithm to optimize the SVM model parameters, which include the kernel parameter σ, non-sensitive loss function parameter ε, and penalty parameter C. We compared the new optimized SVM model with Back Propagation (BP) neural network and common SVM model, using the historical data collected from freeway G5513. The results show that the accu...
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Along with the rapid development of Intelligent Transportation Systems, traffic data collection technologies have progressed fast. The emergence of innovative data collection technologies such as remote traffic microwave sensor, Bluetooth... more
Along with the rapid development of Intelligent Transportation Systems, traffic data collection technologies have progressed fast. The emergence of innovative data collection technologies such as remote traffic microwave sensor, Bluetooth sensor, GPS-based floating car method, and automated license plate recognition, has significantly increased the variety and volume of traffic data. Despite the development of these technologies, the missing data issue is still a problem that poses great challenge for data based applications such as traffic forecasting, real-time incident detection, dynamic route guidance, and massive evacuation optimization. A thorough literature review suggests most current imputation models either focus on the temporal nature of the traffic data and fail to consider the spatial information of neighboring locations or assume the data follow a certain distribution. These two issues reduce the imputation accuracy and limit the use of the corresponding imputation met...
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This paper presents results of a qualitative survey and a quantitative assessment of the relative impacts of transportation journals. The survey involved 80 research university professors, government employees, and practitioners randomly... more
This paper presents results of a qualitative survey and a quantitative assessment of the relative impacts of transportation journals. The survey involved 80 research university professors, government employees, and practitioners randomly chosen to rate a list of peer-reviewed transportation journals. The quantitative assessment consisted of an extensive examination of the impact factor (IF), a widely used metric for comparing scholarly publications, of 30 major transportation journals. Although the Transportation Research Record (TRR) was ranked by far as the most “useful and important” to the work of all those surveyed in the field of transportation, the TRR's IF is lower than those of most other transportation journals. However, compared with other transportation journals, the TRR publishes the most scholarly papers and receives the most citations annually. It is also the most widely accessed by practitioners. This paper explores key factors that affect IF calculations and ide...
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Inductance loop detection systems serve as a primary data source to contemporary traffic information systems. Measures like 20-second or 30-second average velocity, flow, and lane occupancy can be aggregated from individual loop detector... more
Inductance loop detection systems serve as a primary data source to contemporary traffic information systems. Measures like 20-second or 30-second average velocity, flow, and lane occupancy can be aggregated from individual loop detector actuation sampled at 60 Hz typically. Practically, these measures would sometimes be further aggregated into a much lower, e.g. 15-minute, resolution and then the raw data were lost. Valuable traffic information like flow variation may be distorted when the lower resolution aggregation is practiced. A biased conclusion could be drawn from a data integration system consisted of this kind of distortions. Three approaches estimating a peak hour factor based on traffic volume from loop detection systems are introduced in this paper to explore such a quality issue for data integration systems. Peak hour factor is commonly used in Highway Capacity Manual for determining and evaluating future system needs. By processing the raw data with the introduced app...
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Two-way stop-controlled (TWSC) intersections are one of the most common forms of at-grade roadway junctions in the world. These intersections are typically located where a minor road intersects or joins a major roadway and stop signs are... more
Two-way stop-controlled (TWSC) intersections are one of the most common forms of at-grade roadway junctions in the world. These intersections are typically located where a minor road intersects or joins a major roadway and stop signs are placed on the minor approaches. When the major roadway and the traffic that it carries go straight through the intersection, it is a standard TWSC intersection. In many places, however, the prevailing traffic and the major roadway do not continue straight through the intersection. In such cases, the major roadway bends at an angle at the intersection, and the stop signs on the minor streets are placed on adjacent legs of the intersection. These intersections are nonstandard TWSC intersections. Nonstandard TWSC intersections are found frequently in some countries and exist in most. These intersections are officially recognized in traffic codes and manuals in Europe, Australia, and the United States, yet the Highway Capacity Manual (HCM) TWSC procedur...
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Automated enforcement red-light cameras (RLC) have been widely adopted by municipalities around the world as a measure of curbing red-light running (RLR) at signalized intersections and reducing the cost of law enforcement. While a... more
Automated enforcement red-light cameras (RLC) have been widely adopted by municipalities around the world as a measure of curbing red-light running (RLR) at signalized intersections and reducing the cost of law enforcement. While a consensus has not yet been reached about whether RLC in general can benefit intersection safety by reducing RLR and crashes, recent debates revolve around using RLC as a revenue generator. Some of the political backlash of RLC is the perception that they are installed primarily to fulfill revenue guarantees and sustain the RLCprogram. Some municipalities have been charged with changing the signal phasing to trap more red-light runners and increase the revenue from RLC programs. This paper focuses on a number of engineering strategies, mainly related to signal timing that may be used by
municipalities to achieve their financial goals. The negative impacts of implementing these measures on the safety and efficiency of intersection operations and public supporton RLC programs are also
discussed. These strategies are also revealed to increase transparency of the divergent motivations of RLC vendors, municipalities, policy makers and safety advocates.
municipalities to achieve their financial goals. The negative impacts of implementing these measures on the safety and efficiency of intersection operations and public supporton RLC programs are also
discussed. These strategies are also revealed to increase transparency of the divergent motivations of RLC vendors, municipalities, policy makers and safety advocates.
Most literature on short-term traffic flow forecasting focused mainly on normal, or non-incident, conditions and, hence, limited their applicability when traffic flow forecasting is most needed, i.e., incident and atypical conditions.... more
Most literature on short-term traffic flow forecasting focused mainly on normal, or non-incident, conditions and, hence, limited their applicability when traffic flow forecasting is most needed, i.e., incident and atypical conditions. Accurate prediction of short-term traffic flow under atypical conditions, such as vehicular crashes, inclement weather, work zone, and holidays, is crucial to effective and proactive traffic management systems in the context of intelligent transportation systems (ITS) and, more specifically, dynamic traffic assignment (DTA).
To this end, this paper presents an application of a supervised statistical learning technique called Online Support Vector machine for Regression, or OL-SVR, for the prediction of short-term freeway traffic flow under both typical and atypical conditions. The OL-SVR model is compared with three well-known prediction models including Gaussian maximum likelihood (GML), Holt exponential smoothing, and artificial
neural net models. The resultant performance comparisons suggest that GML, which relies heavily on the recurring characteristics of day-to-day traffic, performs slightly better than other models under typical traffic conditions, as demonstrated by previous studies. Yet OL-SVR is the best performer under non-recurring atypical traffic conditions. It appears that for deployed ITS systems that gear toward timely response to real-world atypical and incident situations, OL-SVR may be a better tool than GML.
To this end, this paper presents an application of a supervised statistical learning technique called Online Support Vector machine for Regression, or OL-SVR, for the prediction of short-term freeway traffic flow under both typical and atypical conditions. The OL-SVR model is compared with three well-known prediction models including Gaussian maximum likelihood (GML), Holt exponential smoothing, and artificial
neural net models. The resultant performance comparisons suggest that GML, which relies heavily on the recurring characteristics of day-to-day traffic, performs slightly better than other models under typical traffic conditions, as demonstrated by previous studies. Yet OL-SVR is the best performer under non-recurring atypical traffic conditions. It appears that for deployed ITS systems that gear toward timely response to real-world atypical and incident situations, OL-SVR may be a better tool than GML.
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Abstract: Urban development alongside coastal lines has been growing at a pace exceeding that of new highway construction and improvements to the existing transportation infrastructure. This trend, which is likely to continue, has made... more
Abstract: Urban development alongside coastal lines has been growing at a pace exceeding that of new highway construction and improvements to the existing transportation infrastructure. This trend, which is likely to continue, has made vehicular evacuation of populations in hurricane prone areas increasingly difficult. The experience with Hurricane Floyd in 1999 demonstrated the tremendous magnitude and complexity of the tasks involved in the planning, execution, and management of large-scale evacuations.
Abstract: With shrinking pavement maintenance budgets and increasing maintenance needs, highway agencies are moving toward pavement preventive maintenance (PPM). However, due to the lack of analytical systems and sufficient data, many... more
Abstract: With shrinking pavement maintenance budgets and increasing maintenance needs, highway agencies are moving toward pavement preventive maintenance (PPM). However, due to the lack of analytical systems and sufficient data, many decisions made by highway administrators today are either judgmental or empirical. This paper presents a study of scheduling preventive maintenance (PM) on the project level for different pavement families based on conditions in Beijing, China.
Abstract: The speed limit of 55 mph (88 km/h) is typically used on rural highways in the US For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45 mph (72 km/h)... more
Abstract: The speed limit of 55 mph (88 km/h) is typically used on rural highways in the US For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45 mph (72 km/h) speed limit because, according to AASHTO, running into curbs at high speeds may cause significant vehicular damage and even severe injuries.
Abstract: The Highway Capacity Manual (HCM) 2000 displayed a figure, Exhibit 10-15, for the purpose of forecasting the likely intersection control types (ie, all-ways stop control (AWSC), or two-way stop control (TWSC), and signalization)... more
Abstract: The Highway Capacity Manual (HCM) 2000 displayed a figure, Exhibit 10-15, for the purpose of forecasting the likely intersection control types (ie, all-ways stop control (AWSC), or two-way stop control (TWSC), and signalization) for future facilities. Since this figure is from a source external to HCM, Han et al employed HCM methodologies and established a new set of charts to provide control type selection guidance consistent to HCM delay models for future intersections.
The speed limit of 55mph (88km/h) is typically used on rural highways in the US For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45mph (72km/h) speed limit... more
The speed limit of 55mph (88km/h) is typically used on rural highways in the US For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45mph (72km/h) speed limit because, according to AASHTO, running into curbs at high speeds may cause significant vehicular damage and even severe injuries.
Abstract: Accurate real-time vehicle tracking has a wide range of applications including fleet management, drug/speed/law enforcement, transportation planning, traffic safety, air quality, electronic tolling, and national security. While... more
Abstract: Accurate real-time vehicle tracking has a wide range of applications including fleet management, drug/speed/law enforcement, transportation planning, traffic safety, air quality, electronic tolling, and national security. While many alternative tracking technologies have been developed in the recent years, license plate recognition (LPR) technology is still the simplest and readily available means for uniquely identifying vehicles in more circumstances.
Home Contact Us Directory E-Newsletter Follow Us RSS, About TRB. Annual Meeting. Calendar. Committees & Panels. Programs. Projects. Publications. Resources & Databases. TRID HOME. RECENTLY PUBLISHED. RECENTLY ADDED. ADVANCED SEARCH. New... more
Home Contact Us Directory E-Newsletter Follow Us RSS, About TRB. Annual Meeting. Calendar. Committees & Panels. Programs. Projects. Publications. Resources & Databases. TRID HOME. RECENTLY PUBLISHED. RECENTLY ADDED. ADVANCED SEARCH. New Search; Last Search; Search History; Search Help. RSS FEEDS. SUBMIT PUBLICATION. ABOUT TRID. RESOURCES.
Abstract: One of the most challenging aspects in the Advanced Traffic Management System (ATMS), a major component of Intelligent Transportation Systems (ITS), is to detect and manage traffic incident situations in a reliable and prompt... more
Abstract: One of the most challenging aspects in the Advanced Traffic Management System (ATMS), a major component of Intelligent Transportation Systems (ITS), is to detect and manage traffic incident situations in a reliable and prompt manner to minimize delay, congestion, and incident-related adverse effects. This paper presents a tool developed for the purpose of visualization of incidents with simulated traffic on arterials (VISTA).
Abstract: Through the application of IVHS technologies, particularly the ones related to CVO and ATIS, Driver Information Systems (DIS) can be developed to avoid, or lessen the consequence of, truck accidents. This paper first addresses... more
Abstract: Through the application of IVHS technologies, particularly the ones related to CVO and ATIS, Driver Information Systems (DIS) can be developed to avoid, or lessen the consequence of, truck accidents. This paper first addresses several scenarios as examples of how the DIS may work.
This study investigates the impact of countdown timer on driving maneuvers after the onset of yellow at signalized intersections in China. Signal phasing and traffic operations were videotaped at four comparable intersections under normal... more
This study investigates the impact of countdown timer on driving maneuvers after the onset of yellow at signalized intersections in China. Signal phasing and traffic operations were videotaped at four comparable intersections under normal conditions in Changsha city, China. Microscopic details were extracted to yield 24h worth of data including the onset time of yellow, the onset of red, vehicle location, and maneuvers after the onset of yellow.
Abstract: The complex spatio-temporal behavior of traffic flow has been extensively studied in the last decades. However, most research has primarily focused on freeways, or at most, on urban networks whose facilities are clearly... more
Abstract: The complex spatio-temporal behavior of traffic flow has been extensively studied in the last decades. However, most research has primarily focused on freeways, or at most, on urban networks whose facilities are clearly stratified according to their functionality–freeways, arterials, collectors, and local roads. Research studies on urban reticulated networks, in which several facilities are barely distinguishable with respect to their type of use, have been largely neglected.
Abstract: This paper presents a traffic modeling technique which addresses issues related to vehicle generation, network representation, and vehicle movement. Instead of using conventional time-driven traffic simulation algorithms, this... more
Abstract: This paper presents a traffic modeling technique which addresses issues related to vehicle generation, network representation, and vehicle movement. Instead of using conventional time-driven traffic simulation algorithms, this paper proposes a set of assumptions to enable the implementation of an event-driven traffic simulation algorithm. Both time-and the event-driven algorithms were employed to develop two independent computer simulation software programs for the purpose of comparison.
Automatic incident detection (AID) on freeways has been investigated extensively in the past four decades. Various algorithms covering a broad range of types in regard to complexity, data requirements, and efficiency have been published... more
Automatic incident detection (AID) on freeways has been investigated extensively in the past four decades. Various algorithms covering a broad range of types in regard to complexity, data requirements, and efficiency have been published in the literature. However, a recent nationwide survey concluded that the implementation of AID algorithms in traffic management centers was still limited. The main reasons for this discrepancy were high rates of false alarms and calibration complexity.
Abstract: This study investigates the impact of countdown timer on driving maneuvers after the onset of yellow at signalized intersections in China. Signal phasing and traffic operations were videotaped at four comparable intersections... more
Abstract: This study investigates the impact of countdown timer on driving maneuvers after the onset of yellow at signalized intersections in China. Signal phasing and traffic operations were videotaped at four comparable intersections under normal conditions in Changsha city, China. Microscopic details were extracted to yield 24 hours worth of data including the onset time of yellow, the onset of red, vehicle location, and maneuvers after the onset of yellow.
Abstract: A speed limit of 55 mph (88 km/h) is typically used on rural highways in the US For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a reduced 45 mph (72 km/h)... more
Abstract: A speed limit of 55 mph (88 km/h) is typically used on rural highways in the US For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a reduced 45 mph (72 km/h) speed limit because, according to AASHTO, running into curbs at high speeds may cause significant vehicular damage and even severe injuries.
The effectiveness of an evacuation plan is a central concern of emergency management agencies. Methodologies for assessing and optimizing the space–time use efficiency of an evacuation plan have yet to be studied satisfactorily. To this... more
The effectiveness of an evacuation plan is a central concern of emergency management agencies. Methodologies for assessing and optimizing the space–time use efficiency of an evacuation plan have yet to be studied satisfactorily. To this end, this paper proposes an
assessment metric and uses it for the optimization of evacuation plans. First, we define a space–time use efficiency metric on the basis of trajectories on road segments and intersections. The metric measures the usage of an evacuation network by supporting a trajectory-based analysis of the competing behaviors of vehicles and pedestrians in a hybrid pedestrian-vehicle simulation. Secondly, we present a two-tier hybrid multi-objective optimization algorithm to plan vehicle and pedestrian turning movement directions in an integrated road and building-interior network for the purpose of making decisions about evacuation plans. This algorithm has three objectives: (i) minimizing average evacuation time, (ii) minimizing the overall length traveled, and (iii) maximizing space–time use efficiency in the evacuation network. The stadium at the Wuhan Sports Centre in China and its adjacent road network were chosen as the study environment. A total of 23,362 evacuees and 1362 vehicles were assumed for the evacuation experiments. The analysis results suggest that intra-intersection evacuation flows can significantly influence the
space–time use efficiency of a evacuation plan. The proposed space–time use efficiency evaluation approach provides a practical method of measuring the effectiveness of evacuation plans.
assessment metric and uses it for the optimization of evacuation plans. First, we define a space–time use efficiency metric on the basis of trajectories on road segments and intersections. The metric measures the usage of an evacuation network by supporting a trajectory-based analysis of the competing behaviors of vehicles and pedestrians in a hybrid pedestrian-vehicle simulation. Secondly, we present a two-tier hybrid multi-objective optimization algorithm to plan vehicle and pedestrian turning movement directions in an integrated road and building-interior network for the purpose of making decisions about evacuation plans. This algorithm has three objectives: (i) minimizing average evacuation time, (ii) minimizing the overall length traveled, and (iii) maximizing space–time use efficiency in the evacuation network. The stadium at the Wuhan Sports Centre in China and its adjacent road network were chosen as the study environment. A total of 23,362 evacuees and 1362 vehicles were assumed for the evacuation experiments. The analysis results suggest that intra-intersection evacuation flows can significantly influence the
space–time use efficiency of a evacuation plan. The proposed space–time use efficiency evaluation approach provides a practical method of measuring the effectiveness of evacuation plans.
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The September 11 attacks have made clear that the likelihood of occurrence of many previously thought low-probability events, such as for example a radiological event at a nuclear plant or the release of toxic gases to the atmosphere,... more
The September 11 attacks have made clear that the likelihood of occurrence of many previously thought low-probability events, such as for example a radiological event at a nuclear plant or the release of toxic gases to the atmosphere, have to be reassessed. To protect the population that could be potentially affected by this type of man-made disasters (as well as natural disasters such as hurricanes, earthquakes, forest fires), vehicular evacuation is one alternative that needs to be evaluated.
The efficient and reliable flow of urban goods and services is essential for the economic well-being of the United States (US), particularly the majority of Americans who live in urbanized areas. According to recently published estimates... more
The efficient and reliable flow of urban goods and services is essential for the economic well-being of the United States (US), particularly the majority of Americans who live in urbanized areas. According to recently published estimates (FAF3, 2007), the US freight system moves about 19 billion tons of goods valued at $17 trillion in 2007. These shipments result in a total of 5.7 trillion ton-miles of movements during the same year.
This paper demonstrates that in addition to intracycle demand fluctuation, which is already a consideration in many delay models, intercycle demand variance also impacts average delay at signalized intersections. Webster-type delay models... more
This paper demonstrates that in addition to intracycle demand fluctuation, which is already a consideration in many delay models, intercycle demand variance also impacts average delay at signalized intersections. Webster-type delay models treat demand fluctuation over the whole analysis period, often 15 min or longer, as if it were just within a single cycle. Such an approach is fine if used judiciously, one might presume. However, results from Monte Carlo simulations with the incremental queue accumulation IQA method indicate that Webster-type delay models will underestimate the average delay under heavy traffic conditions. As unutilized capacity at a signalized intersection cannot be saved or carried over to be used by succeeding cycles when demand surges due to normal fluctuation,
better understanding of the patterns of intercycle demand variance is important. Simulation results demonstrate that different patterns of
intercycle demand variance can result in different levels of average delay. A low-to-high demand pattern will cause a higher average delay than a high-to-low pattern would, even though the overall demand level is exactly the same. It is therefore clear that neglecting intercycle demand variance may lead to significant inaccuracy and, hence, suboptimal signal timing decisions.
better understanding of the patterns of intercycle demand variance is important. Simulation results demonstrate that different patterns of
intercycle demand variance can result in different levels of average delay. A low-to-high demand pattern will cause a higher average delay than a high-to-low pattern would, even though the overall demand level is exactly the same. It is therefore clear that neglecting intercycle demand variance may lead to significant inaccuracy and, hence, suboptimal signal timing decisions.
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Research Interests: Bioinformatics, Natural Language Processing, Machine Learning, Data Mining, Signal Processing, and 11 moreNetwork Security, Text Mining, Computer Security, Mobile Computing, Vehicle Tracking Systems, Automatic License Plate Detection Using Image Processing, Tracking Vehicles in Real Time, License Plate Matching, Syntactic and Semantic Knowledge, Vehicle Tracking, and Edit Distance
Traffic signal timing would be a trivial undertaking if demand were constant and uniform. Once stochastic factors and demand fluctuation are taken into consideration, however, the optimization of signal timing becomes challenging, if not... more
Traffic signal timing would be a trivial undertaking if demand were constant and uniform. Once stochastic factors and demand fluctuation are taken into consideration, however, the optimization of signal timing becomes challenging, if not impossible, even for an isolated, fixed-time signal. To answer the question of whether a longer cycle—more than 150 s, for example—or a shorter one—less than 60 s, for example—is better under fluctuating demand conditions, a probabilistic approach is employed to study minimal average delay by the ...
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Abstract The study examined the extent of cross-disciplinarity in nanotechnology and transportation engineering research. Researchers in these two fields were determined from the web sites of the US News and World Report top 100 schools... more
Abstract The study examined the extent of cross-disciplinarity in nanotechnology and transportation engineering research. Researchers in these two fields were determined from the web sites of the US News and World Report top 100 schools in civil engineering and materials science. Web of Science searches for 2006 and 2007 articles were obtained and the journals in which the articles appeared were classified using Library of Congress call numbers.
Concerning the incomplete information, structural characteristics and driver's habit, issue of the shortest path search in road network was studied. A mixed programming was proposed combining the global and local planning. During... more
Concerning the incomplete information, structural characteristics and driver's habit, issue of the shortest path search in road network was studied. A mixed programming was proposed combining the global and local planning. During global planning, an index d/l was introduced which represented the ratio of Origin-Destination(OD) distance to the average link length, elliptical minimal search area was determined by d/l, and the initial global shortest path was calculated by Dijkstra algorithm. During local planning, an improved ...