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Abstract

In this study, a methodology for finding a time-dependent evacuation strategy is developed. When an emergency happens, all people in the influenced area want to escape as soon as possible, so an extremely converged departure pattern arises. Because the capacity of transpo...Lead moreIn this study, a methodology for finding a time-dependent evacuation strategy is developed. When an emergency happens, all people in the influenced area want to escape as soon as possible, so an extremely converged departure pattern arises. Because the capacity of transportation road network is designed to serve the normal level of travel demand, the abnormal travel demand cannot be handled by the network and severe traffic jam would be expected, which engenders numerous evacuees’ lives. In this work, a sequential evacuating strategy for using a limited network capacity in a more efficient way is proposed. An optimal time-dependent staged evacuation plan which minimizes network clearance time is found by Genetic Algorithm. The developed framework is applied to a test network and the results show that the optimal strategy is effectively using the network capacity with the least network clearance time and also the model is stable with various levels of evacuating demands.

Abstract

Car navigation systems are in widespread use in Japan and drivers often drive while processing information from them and other onboard devices. There is concern that this may distract the driver’s attention during driving. To determine the level of distraction from such d...Lead moreCar navigation systems are in widespread use in Japan and drivers often drive while processing information from them and other onboard devices. There is concern that this may distract the driver’s attention during driving. To determine the level of distraction from such devices, many researchers are carrying out evaluation tests in which they use surrogate tasks instead of actual information processing tasks in order to simplify the test conditions. Though many surrogate tasks are being used, comparisons of the mental workload levels with various tasks has not been sufficiently discussed. To reveal the differences in workload, in this study we measured mental workload levels during 11 tasks by having subjects rotate a disk 6 cm in diameter or respond to sudden stimuli. The differences between the tasks were measured by subjective evaluation of subjects, rotating time variance, and response time.

Abstract

Traffic congestion occurs when the volume of traffic on a roadway is high. In this condition, vehicle speeds are reduced and driving time is increased . This model can be used for establishing the safe traffic policy to reduce the traffic accidents. Especially, it can be ...Lead moreTraffic congestion occurs when the volume of traffic on a roadway is high. In this condition, vehicle speeds are reduced and driving time is increased . This model can be used for establishing the safe traffic policy to reduce the traffic accidents. Especially, it can be useful for the prevention of dangerous accidents on a slippery road, where snow or ice is not completely removed. Traffic signal control is also one of these applications that is used for reducing traffic congestion. We can see much traffic congestion happened on intersection of downtown. In Korea, traffic congestion is very serious because of wrong traffic control signal. In this paper, therefore, we will analyze traffic circumstance in real-time and solve traffic congestion. In this paper, to improve average vehicle speed and reduce average vehicle waiting time, we created optimal green time using fuzzy rules and neural networks. Computer simulation results proved reducing average vehicle waiting time, because proposed coordinating green time is better than electro-sensitive traffic light system which does not consider coordinating green time.

Abstract

The previous study based on driving simulator experiments evaluated the fuel-consumption reduction effects of eco-driving instructions and the introduction of a fuel-consumption meter (FC-meter). Since the sustainability of these effects remains unclear, the present paper...Lead moreThe previous study based on driving simulator experiments evaluated the fuel-consumption reduction effects of eco-driving instructions and the introduction of a fuel-consumption meter (FC-meter). Since the sustainability of these effects remains unclear, the present paper conducts simulator experiments to evaluate the long-term effects of the eco-driving instructions and the introduction of an FC-meter on the improvement of fuel economy.

Abstract

Dynamic traffic management (DTM) monitors the traffic situation and tries to optimize it by applying different control measures like speed limits, route guidance, lane closure, ramp metering, intersection control or others to the traffic network. Vital for the DTM cycle i...Lead moreDynamic traffic management (DTM) monitors the traffic situation and tries to optimize it by applying different control measures like speed limits, route guidance, lane closure, ramp metering, intersection control or others to the traffic network. Vital for the DTM cycle is traffic data collection to enable the feedback loop to traffic operations. Roadside detection is nowadays the most common way of traffic data collection, but probe vehicle data, GSM data and vehicle to infrastructure communication are getting more and more momentum. With the new variety in data collection methods, research on data fusion, to combine different data sources to better traffic state information increases, but the detector placement problem is a less explored research topic in transportation. In this paper we will describe a framework for detection installation assessment on highway networks, taking into account the infrastructure, demand and authority policies. In a first step we will present algorithms to automatically detect points of interest in the network that require more dense detection as a starting point for practitioners to define the policy based level of information they require for the network. The level of information can be defined by adjusting data demand functions resulting from the analysis. Placed detectors in the network are represented with data supply functions based on the sensor technology and measurement entity. A comparison of both functions for each link in the entire network will result in a level of detection that can be used to assess detection installation objective.

Abstract

Intelligent Transportation Systems (ITS) are generally complex and naturally difficult for development. Existing ITS architectures such as KAREN or the National ITS Architecture can be used to facilitate ITS development. They can mainly describe systems by using data cent...Lead moreIntelligent Transportation Systems (ITS) are generally complex and naturally difficult for development. Existing ITS architectures such as KAREN or the National ITS Architecture can be used to facilitate ITS development. They can mainly describe systems by using data centric methodology and data flow model. However, this methodology is inflexible for complicated requirement and inconvenient in case of various systems interoperability because of number of connections and entity types. This paper proposes an ITS architecture model which can reduce existing ITS architecture problems by using characteristics and benefits of object oriented methodology and UML to model complicated requirements such as regulation or new specific component adding and to decrease number of connections of systems interoperability. Additionally, this paper illustrates a comparison between both methodologies by using real example cases as well.

Abstract

A SAM is vital component in the transportation card system which is inserted in the payment terminal. As it is communicating with the transportation card, we can have the transaction process which we pay the transportation fare fee. As transportation card market grows, ma...Lead moreA SAM is vital component in the transportation card system which is inserted in the payment terminal. As it is communicating with the transportation card, we can have the transaction process which we pay the transportation fare fee. As transportation card market grows, many transportation agency start up their business with their own technique. If the transportation card and a PSAM are issued by the same company, it works well. But, in the other cases it doesn't work. Thus this paper propose a standard PSAM based on Korea Industry Standard (KS X 6923) in the OCAP card (One Card All Pass in Korea) system which can communicate every OCAP card issued by various different transportation agencies. It makes possible that we can use any transportation service regardless areas with one card, the OCAP card.

Abstract

This paper demonstrates the results of field tests for the assessments of cooperative intersection signal violation warning system (CISVWS). The system consists of hardware including in-vehicle warning device, roadside antenna, and traffic signal controller and software t...Lead moreThis paper demonstrates the results of field tests for the assessments of cooperative intersection signal violation warning system (CISVWS). The system consists of hardware including in-vehicle warning device, roadside antenna, and traffic signal controller and software to operate and test the cooperative system through vehicle to infrastructure (V2I) communication systems. Field tests were fulfilled under the real traffic situations in order to test the system in terms of signal violation warning initiation time from the signal controller, the activation and duration of OBE, and warning delay based on the relationships between distance variables including safe stopping distance and the location of RSE. Findings from the field test at the two sites of signalized intersections indicated that the system would be implemented in reducing red light violation and intersection collision through the in-vehicle warning device at signalized intersection.

Abstract

In this study, waiting time of bus at intersection for active bus signal priority was modeled according to detector location and expectation of waiting time was calculated for detector location that can minimize bus delay. With differentiated application of bus speed and ...Lead moreIn this study, waiting time of bus at intersection for active bus signal priority was modeled according to detector location and expectation of waiting time was calculated for detector location that can minimize bus delay. With differentiated application of bus speed and detector location, the change of bus delay was observed. Detector location showing the minimum bus delay according to change of bus speed was inspected. In addition, this study analyzed the active bus signal priority using a microscopic simulation under the same conditions with the formula analysis. This allowed the determination that bus delay can be changed only with a change in detector location even if there is no change in the delay of passenger car.

Abstract

ABSTRACT Tilt correction is a very crucial and inevitable task in the automatic recognition of the vehicle license plate (VLP). In this paper, according to the least square fitting with perpendicular offsets (LSFPO), the VLP candidate region is fitted to a straight line. ...Lead moreABSTRACT Tilt correction is a very crucial and inevitable task in the automatic recognition of the vehicle license plate (VLP). In this paper, according to the least square fitting with perpendicular offsets (LSFPO), the VLP candidate region is fitted to a straight line. After the line slope is obtained, rotation angle is estimated. Then the whole image is rotated for tilt correction by this angle. Despite the success of VLP detection approaches in the past decades, a few of them can effectively locate license plate (LP), even when vehicle bodies and LPs have similar color. A common drawback of color-based VLP detection is the failure to detect the boundaries or border of LPs. To overcome a common drawback, in this paper, we propose a modified recursive labeling algorithm for solving this problem and detecting candidate regions. According to different colored LP, these candidate regions may include LP regions; geometrical properties of LP are then used for classification. For the decomposing candidate regions, predetermined alphanumeric characters are used by position histogram to verify and detect vehicle LP regions. Various LP images were used with a variety of conditions to test the proposed method and results proved its effectiveness.

Abstract

In this paper, we propose and simulate an intelligent transportation system (ITS) employing multi-hop cooperative communication scheme for enhancing system performance. Streetlights are adopted as the relays for multi-hop communications in the ITS. It is assumed that visi...Lead moreIn this paper, we propose and simulate an intelligent transportation system (ITS) employing multi-hop cooperative communication scheme for enhancing system performance. Streetlights are adopted as the relays for multi-hop communications in the ITS. It is assumed that visible light is used for lighting up the street and streetlights utilized in this paper can perform visible light communication (VLC). It is also assumed that a communication channel is an optical wireless channel. The system performance is evaluated in terms of bit error probability. And the system performance of the proposed system is compared with that of a single-hop communication system. Form simulation results, it is shown that the performance of the single-hop system decreases significantly as the distance between the transmitter and the receiver increases. However, the proposed system shows almost uniform performance regardless of distance between a transmitter and a receiver. In addition, it is confirmed that, in spite of the low power consumption, the proposed ITS employing multi-hop relays shows better performance than the single-hop system does irrespective of distance between the transmitter and the receiver. The results in this paper are of interest in cooperative communication-based ITS applications.

Abstract

The space-time relationship is an essential aspect for the road traffic prediction in Intelligent Transport Systems. In this paper, we propose a new method to determine the spatial correlation on the transportation road network. Firstly, the traffic congestion indicator i...Lead moreThe space-time relationship is an essential aspect for the road traffic prediction in Intelligent Transport Systems. In this paper, we propose a new method to determine the spatial correlation on the transportation road network. Firstly, the traffic congestion indicator is presented for normalizing the traffic condition in a spatial area. Secondly, considering the different road connection types, we build the spatial correlation matrix by statistical learning method based on the historical traffic data. Thirdly, STARMA (Space-Time Auto Regressive Moving Average) is employed for the traffic prediction model building. We use the historical traffic data of 7 months for the practical experiment. The data of the first 6 months is adopted for prediction model building, and the data of the last month is used for the model evaluation. By the prediction accuracy comparison, the STARMA model based on this method is superior to AR (Auto Regressive) models for traffic prediction.

Abstract

This paper describes how and where a traffic detector, mainly used for real-time traffic management and information systems, is evaluated in Korea. Traditionally, detector evaluation in Korea is based on video ground-truth data. However, the increasing demand for real-tim...Lead moreThis paper describes how and where a traffic detector, mainly used for real-time traffic management and information systems, is evaluated in Korea. Traditionally, detector evaluation in Korea is based on video ground-truth data. However, the increasing demand for real-time traffic management and information has resulted in increased focus on rapid and high-throughput detector evaluation?impossible with the conventional video method. Hence, the Korean government established a national traffic detector testbed equipped with a laser-based baseline data source, relational database, video acquisition system, communication infrastructure, and so forth. The laser-based baseline data source is thoroughly verified using tape-switch sensors with an oscilloscope and two-way ANOVA. The testbed is actively used in evaluating the vehicle-level performance of many in-road and over-road traffic detectors through consensus-based data verification. A comprehensive discussion on detector performance tests using the testbed is presented. The testbed developed in this research is expected to make traffic detector evaluation much easier than before.

Abstract

Fusion of probe and fixed sensor data has been widely used to estimate travel time on urban arterials. Considering different accuracies and limitations of traffic data from various sources, data fusion is applied to extend the spatial and temporal coverage of data. Majori...Lead moreFusion of probe and fixed sensor data has been widely used to estimate travel time on urban arterials. Considering different accuracies and limitations of traffic data from various sources, data fusion is applied to extend the spatial and temporal coverage of data. Majority of existing fusion techniques to estimate travel time are merely based on statistical methods without considerations for traffic engineering concepts. In addition, probe trajectories include much richer information of traffic conditions rather than only travel times, which could be used more effectively. In this research a data fusion technique is proposed to estimate vehicle trajectories using multi-sensor traffic data and concepts of traffic engineering which can fully utilize probe trajectory information. Proposed method is based on modeling vehicle trajectories by applying the simplified theory of 3D kinematic waves. Assuming a triangular shaped flow-density curve, variational formulation of kinematic waves is considered to estimate cumulative number of vehicles in time and space. Given cumulative number of vehicles as heights, a three dimensional surface is created over time-space plane and vehicle trajectories are estimated as contours of the surface. Once vehicle trajectories are estimated, they can be used for several purposes including travel time estimation and signal timing optimization. Performance of the methodology regarding travel time estimation is evaluated and it is shown that it is capable of estimating reliable travel times on urban arterials. At the end application of the methodology for signal timing optimization is demonstrated.

Abstract

This paper describes the development and evaluation of Project Adapted Scheduling Algorithm for the On-demand Bus System. On-Demand Bus is a Demand Responsive Transit service where the vehicles will transport users after they reserve their seats, and the vehicle will not ...Lead moreThis paper describes the development and evaluation of Project Adapted Scheduling Algorithm for the On-demand Bus System. On-Demand Bus is a Demand Responsive Transit service where the vehicles will transport users after they reserve their seats, and the vehicle will not move if there is no reservation. In order to answer the complicated requirement to the On-demand Bus scheduling algorithm from each project, the project adapted scheduling algorithm is developed and evaluated by the computer simulation experiment. According to the result of computer simulation, the proposed scheduling algorithm performed as designed and it is proved that the developed scheduling algorithm can calculate the schedule of the On-demand Bus in answering the complicated requirement of project by coordinating the parameter.

Abstract

This paper describes the effects of a driver’s conversation and visual search on eye-fixation-related potential (EFRP). Experiments are conducted with a driving simulator. Electroencephalogram (EEG) is performed when the participants were assigned a driving task and a cog...Lead moreThis paper describes the effects of a driver’s conversation and visual search on eye-fixation-related potential (EFRP). Experiments are conducted with a driving simulator. Electroencephalogram (EEG) is performed when the participants were assigned a driving task and a cognitive task concurrently. Cognitive tasks include conversation, visual search, and manipulation of a mobile phone. EFRP is calculated by averaging the EEG waves whose offsets are determined by saccadic eye movements. The amplitude of the EFRP signal is used for estimating the level of a driver’s distraction. The results show that the amplitude of lambda response in EFRP decreases when considerable attention is required to execute a cognitive task. Simulation results using the obtained ERRP data are also discussed.

Abstract

Short distance trips are crucial for urban mobility and accessibility. They can contribute to integrated transportation (the “last mile” problem), and more generally to urban ad-hoc ride sharing scenarios. Since no transport provider covers short distance trips where dema...Lead moreShort distance trips are crucial for urban mobility and accessibility. They can contribute to integrated transportation (the “last mile” problem), and more generally to urban ad-hoc ride sharing scenarios. Since no transport provider covers short distance trips where demand arises, private car use is flourishing in recent decades, with all the known disadvantages of traffic congestions, resource wastes, air pollution, and insufficient parking space especially in city centers. Taxis are focusing on providing a door-to-door service, but they do not perform well in short distance trip pickup and delivery services. This paper identifies the obstacles, and suggests the empty cruise time of taxis as (a) a feasible solution for the short distance trip problem, and (b) a contribution to develop a short distance trip market for the taxi industry. This empty cruise contribution hypothesis is investigated by testing different models that define ad-hoc matches of passengers and empty cruising taxis. An agent-based simulation is designed to study the match probability by these models. Based on the experimental results it is shown that taxi empty cruise match models have the potential to solve the short distance problem and to develop the taxi short distance trip markets.

Abstract

We propose a multiagent interpolation system for traffic conditions that includes estimation and learning agents. These agents are allocated to all the road links. The Normalized Velocity (NV) is used in this system. Estimation agents renew the NV for each road link, and ...Lead moreWe propose a multiagent interpolation system for traffic conditions that includes estimation and learning agents. These agents are allocated to all the road links. The Normalized Velocity (NV) is used in this system. Estimation agents renew the NV for each road link, and learning agents renew the weight values for estimation. The weight values can be calculated by multivariate analysis. Estimation and learning agents alternately calculate the results to improve the interpolation accuracy. The coefficient of determination and mean square error are used to evaluate the interpolation accuracy. The obtained probe car data is stored in the learning database. In this study, we change an HDD-type (Hard Disk Drive type) learning database into a memory-type one to improve the performance. The processing time becomes 1/30, when the memory-type leaning database is used. The average standard deviation of the estimated velocity error becomes 7.34 km/h in the evaluation area.

Abstract

The smart highway project, launched by the South Korean government, will deliver higher safety, mobility, convenience, and comfort, and is expected to address traffic congestion, road accidents, and other challenges as it meets the future demand for smart roads. In order ...Lead moreThe smart highway project, launched by the South Korean government, will deliver higher safety, mobility, convenience, and comfort, and is expected to address traffic congestion, road accidents, and other challenges as it meets the future demand for smart roads. In order to achieve these goals, a large amount of information is needed, including road conditions, vehicle status, driver conditions, and other useful data. In this paper, an experimental study aimed at detecting different road conditions (dry and wet) using a 94 GHz dual-channel polarimetric radiometer was conducted in an open-air laboratory, with an asphalt road surface as the target. Here, brightness temperatures are measured at horizontal and vertical polarizations for different road surface conditions. The measurements carried out on the target confirm that a 94 Ghz band polarimetric radiometer is able to detect different road surface conditions. In addition, it also demonstrates a more detailed description of dry and wet road surface conditions is possible. As such, use of a radiometer is expected to assist in the prevention of traffic accidents by offering rapid and accurate information to drivers.

Abstract

Factors that influence travel planning and route choice decision include route attributes, personal characteristic, trip characteristics, and environment condition. To inform road users with the travel information, travel planning system requires advanced computers, elect...Lead moreFactors that influence travel planning and route choice decision include route attributes, personal characteristic, trip characteristics, and environment condition. To inform road users with the travel information, travel planning system requires advanced computers, electrical technologies and robust traffic models. Intelligent transport systems (ITS) are one of the limited responses remaining to reducing traffic congestion in conjunction with collecting traffic data. This study evaluates route attributes which include travel time, travel distance and fuel consumption/emission. Global Positioning System (GPS) was adapted for data collection on an elevated expressway and alternative road. Six probe vehicles were equipped with GPS and data-logger to gather second-by-second travel data such as speed, time and location. The vehicles were also governed to travel on the selected parallel route. Besides of riding quality, the paper also examined travel time and distance trajectories and driving cycle to estimate instant fuel consumption and pollutant emissions using the a SIDRA-TRIP integrated GPS model. Second-by-second fuel consumption and pollutant emissions were then estimated. The results showed that fuel consumption and emission outputs travelled on the expressway route were lower than those travelled on the at-grade route. However, the SIDRA-TRIP model is required careful calibration and validation to replicate Thailand’s traffic conditions.

Abstract

This paper presents an overview for a multi-hop communication system onboard freight trains based on wireless sensor networks (WSNs). Because a WSN with nodes in each freight car has a linear chain-like topology of significant length, the existing IEEE 802.15.4 communicat...Lead moreThis paper presents an overview for a multi-hop communication system onboard freight trains based on wireless sensor networks (WSNs). Because a WSN with nodes in each freight car has a linear chain-like topology of significant length, the existing IEEE 802.15.4 communication protocol, assuming a star topology, is unable to provide acceptable service. The end-to-end communication between nodes relies on individual nodes communicating with their respective neighbors to carry the information over multiple hops and deliver it to the desired destination. The routing performance and reliability degrades significantly with the increasing number of hops. We propose a practical solution for large-scale multi-hop wireless sensor networks in railroad environments that overcomes this problem. Our simulation results show that our proposed multi-tier communication approach is a feasible and reliable solution for implementing chain-topology WSNs with a high number of hops onboard freight trains. The protocol, based on the IEEE 802.15.4 network stack, is implemented and tested in ns-2.

Abstract

Cellular phone positioning technologies have been used as traffic monitoring tools but focused on real-time auto travel time and speed measurements. This paper demonstrates the other potential of cellular phone technologies in traffic survey studies based on a long-term o...Lead moreCellular phone positioning technologies have been used as traffic monitoring tools but focused on real-time auto travel time and speed measurements. This paper demonstrates the other potential of cellular phone technologies in traffic survey studies based on a long-term observation data covering the Washington DC metropolitan area. Individual travel behavior tracking and characteristics identification algorithms were proposed and demonstrated by tracking cellular phones generated from the Reagan International Airport. The traffic dispersion distribution from the airport was also investigated. The technology analysis and demonstration process indicated that cellular phone positioning systems can provide acceptable location information and was feasible to track individual travel behavior and estimate travelers’ characteristics. It also can be used to realize the traffic impact or roughly determine truck volumes from a target facility. Furthermore, a long-term observation can increase the sample cellular phone size. A detailed land use and special objects database is needed to enhance the accuracy of travelers’ characteristics identification. Field data collection for verification and calibration of traffic tracking and classification is also essential for the further study.

Abstract

Traffic engineers have been using a wide variety of road signs and pavement markings to enhance the safety of road users. But the numbers of pedestrian and bicyclist (P/B) crashes and fatalities are still astonishing. More must be done to maximize the safety of P/B using ...Lead moreTraffic engineers have been using a wide variety of road signs and pavement markings to enhance the safety of road users. But the numbers of pedestrian and bicyclist (P/B) crashes and fatalities are still astonishing. More must be done to maximize the safety of P/B using latest technologies. This paper introduces the advanced traffic devices that make the interchange crossing safer for the pedestrians and bicyclists. These devices can help detect the occurrence of traffic and increase the motorist awareness of P/B. A diamond interchange in Texas, USA is considered as an example where problems faced by the P/B while crossing the interchange are identified, and sample treatments that use the advanced traffic devices introduced in this paper are proposed.

Abstract

In the ITS Strategic Research Plan, 2010-2014, recently released by the U.S. Department of Transportation’s Research and Innovative Technology Administration, one of the key components identified for success of IntelliDrive and other ITS applications is assurance that the...Lead moreIn the ITS Strategic Research Plan, 2010-2014, recently released by the U.S. Department of Transportation’s Research and Innovative Technology Administration, one of the key components identified for success of IntelliDrive and other ITS applications is assurance that the privacy of consumers will be protected. Ongoing research by the authors show that privacy issues can be a significant impediment to the adoption and use of Intelligent Transportation Systems (ITS) and Location Based Services (LBS). This paper will build on current research and provide an analysis of existing privacy policies as currently offered to consumers by public and private providers of ITS and LBS. The paper will describe the process by means of which a rich archive of existing privacy policies is created. We than undertake a statistical analysis of this archive, with the goal of identifying what types of responsibilities are commonly assigned to users and providers in terms of privacy protection (such as opt-in vs. opt-out provisions), the technological measures that are in place to provide privacy protections, and how users are notified of these measures and the recourses that users have if

Abstract

Dynamic Message Signs (DMS) are the most visible Intelligent Transportation System (ITS) devices on the road. An important measure of the value of a DMS message is its credibility. Correctness, timeliness and usefulness of the message constitute its credibility. It is vit...Lead moreDynamic Message Signs (DMS) are the most visible Intelligent Transportation System (ITS) devices on the road. An important measure of the value of a DMS message is its credibility. Correctness, timeliness and usefulness of the message constitute its credibility. It is vitally important that travelers believe that a message displayed on a DMS is based on fact and accurately describes present roadway conditions. The goal of the research is to qualitatively compare the messages displayed on the DMSs to the data revealed by the Bluetooth sensors in order to measure the quality and effectiveness of the messages. Bluetooth sensors take samples of the travelling vehicles and are capable of providing both travel time and origin destination data on freeway segments. Details of analysis for a case study with three messages are presented. Timeliness and accuracy of the messages are evaluated based on the collected ground truth data. Results show that Bluetooth sensors are powerful and flexible tools for dynamic message sign evaluation.

Abstract

This paper investigates the potential of advanced signal processing techniques in determining the transportation network critical routes for control purpose. The proposed method can be considered as alternative to the orthodox O-D estimation methods. During the peak perio...Lead moreThis paper investigates the potential of advanced signal processing techniques in determining the transportation network critical routes for control purpose. The proposed method can be considered as alternative to the orthodox O-D estimation methods. During the peak periods certain movements in the network are considered significant based on their location (i.e. entry and exit points) and flow fluctuation. The proposed method considered observed counts profiles resulting from the peak demand and signal operation as non-stationary time series. Wavelet domain processing is used to decompose, de-noise, compress, and extract the common pattern in a set of traffic flow time series collected from several detectors in signalized sub-network in Reston Parkway in Northern Virginia. Results show that several matched patterns in movements can be detected. The obtained route’s pattern matches the field observation. The proposed method can identify the critical route under the congested conditions without rely on traditional O-D estimation method.

Abstract

In general, the operation of large trucks involves many different types of maneuvers. The “backing maneuver,” in particular, requires a higher level of driver attention due to a limited rear view. A growing number of trucks in the U.S. is equipped with rearview video syst...Lead moreIn general, the operation of large trucks involves many different types of maneuvers. The “backing maneuver,” in particular, requires a higher level of driver attention due to a limited rear view. A growing number of trucks in the U.S. is equipped with rearview video systems (RVS) that can help the driver see much of the area behind the vehicle. Rearview video systems consist of one or more cameras and one monitor. It is expected that a rearview video system can help drivers reduce potential backing crashes. To evaluate the effectiveness of the system, this study performed a controlled driver test with 45 truck drivers. The test used three backing maneuvers and a pedestrian dummy to observe the potential crashes. The results showed that the use of an RVS increased the stop rate of the drivers during the Straight Line Backing manuever by 46.7 percent, which can be interpreted as the increase in odds of avoiding potential backing crashes during the backing maneuver. The stop rate increased 4.4 percent and 17.8 percent for the Offset Right Backing and Alley Dock Backing maneuvers, respectively. Driver age, commercial driving experience, and previous experience with an RVS did not show any statistical association with the increased stop rate, which means an RVS can be adopted by drivers quickly. In general, drivers showed positive attitudes toward using an RVS, and more than 90 percent of respondents agreed that an RVS can reduce the rear blind spot for large trucks.

Abstract

Green House Gas (GHG) tax is considered to be one of the countermeasures for global warming and climate changes that are known to be outcomes of GHG emissions. And transportation is responsible for substantial portion of GHG emissions and, thus, many countries are now imp...Lead moreGreen House Gas (GHG) tax is considered to be one of the countermeasures for global warming and climate changes that are known to be outcomes of GHG emissions. And transportation is responsible for substantial portion of GHG emissions and, thus, many countries are now implementing the effectiveness of GHG tax on transportation. For reliable evaluation of GHG tax policy, it is required to better understand the influence of GHG tax on travelers' behavior. This paper uses multinomial mixed logit model to analyze travelers' mode choice behavior for the Green House Gas (GHG) tax. The model examined how travelers perceive GHG tax and travel cost, and how traveler groups with different attributes react to GHG tax. Heterogeneous travelers' perceptions were observed in both GHG tax and travel cost but travelers were more sensitive to GHG tax than travel cost. The analysis also shows significant distinctions between different traveler groups when categorized by income level and interest level in environment. The implications for GHG tax policy were drawn from the findings and summarized in the paper.

Abstract

Most Intelligent Transportation Systems (ITS) have adopted data privacy policies to assure patrons they will not be held to a higher level of scrutiny or regulatory compliance because of voluntarily adopting ITS technology. That may be changing. In two recent and high-pro...Lead moreMost Intelligent Transportation Systems (ITS) have adopted data privacy policies to assure patrons they will not be held to a higher level of scrutiny or regulatory compliance because of voluntarily adopting ITS technology. That may be changing. In two recent and high-profile deployments, the issue of the patron’s right to privacy is being significantly questioned. The outcome of these instances will have significant and policy-setting implications on ITS participation rates and the concomitant achievements of energy reduction, improved safety air quality, and congestion relief. As well, perhaps, the willingness of the private sector to invest in new programs may be affected as the absence of data privacy lessens the value equation for users and the payback for investors. Forced government access is akin to killing the goose that laid the golden egg: The value of ITS programs to users will be lessened and participation levels will decline, reducing in turn the social benefits for which the programs were originally deployed.

Abstract

Short-lived, unlinked certificates are introduced to provide secure and privacy-preserving communications in vehicle networks. A short-lived certificate has a short expiration period on the order of weeks, days, or even shorter time durations, and uniquely belongs to one ...Lead moreShort-lived, unlinked certificates are introduced to provide secure and privacy-preserving communications in vehicle networks. A short-lived certificate has a short expiration period on the order of weeks, days, or even shorter time durations, and uniquely belongs to one vehicle. Each vehicle has a large number of short-lived certificates. It randomly selects a certificate to use on a “just-in-time” basis to sign or encrypt outgoing messages. Short-lived certificates are unlinked to the vehicle in that no single entity in the network will have sufficient information to determine which vehicle owns which certificate or which set of certificates belong to the same vehicle. These properties make it infeasible for the attacker to uncover vehicle identities by promiscuously collecting and linking certificates. Because each certificate uniquely belongs to a single vehicle, only one vehicle is affected if a certificate is compromised. Finally, short-lived certificates eliminate the need for certificate revocation lists (CRLs), whose size and timely distribution presents a difficult challenge in any Public-Key Infrastructure (PKI) system. In this paper, we discuss the goals and design principles of short-lived, unlinked certificates. We present a new certificate authority (CA) architecture and its enabling transaction flows for managing short-lived, unlinked digital certificates throughout their lifecycles in vehicle networks. The presented architecture partitions the traditional CA functions into authorizing CA and assigning CA. This allows the timely and precise identification of the compromised vehicle from a misused certificate while protecting vehicle identifies even when the assigning CA is compromised.

Abstract

In recent years, there has been increasing interest in inter-vehicle communications (IVC) based on wireless networks to collect and distribute traffic information in various Intelligent Transportation Systems applications. In this paper, we study the performance of IVC un...Lead moreIn recent years, there has been increasing interest in inter-vehicle communications (IVC) based on wireless networks to collect and distribute traffic information in various Intelligent Transportation Systems applications. In this paper, we study the performance of IVC under various traffic and communication conditions by means of simulation analysis. We consider impacts of shock waves, transportation network, traffic densities, transmission ranges, and multiple information sources. We used a state-of-the-art communication network simulator ns-2 to measure success rate and message delivery ratio (MDR) for flooding-based IVC communication. For reasonable realism in the deployment scenario, we assume that only a partial set of vehicles on the road are equipped with communication devices, according to the market penetration rate. A Monte-Carlo simulation method is used with repeated random sampling of IVC-equipped vehicles. The results indicate how these parameters can impact the performance of IVC communications. By comparing the flooding-based approach (theoretical and simulation) and simulation results using AODV (Ad Hoc On-Demand Distance Vector), we conclude the importance of traffic environment and network protocol for IVC communication.

Abstract

This paper presents a methodology for estimating the incident duration and identifying its critical contributing factors in the state of Maryland. The incident database from Year 2003 to Year 2006 from the Maryland State Highway (MDSHA) and Police Accident Report database...Lead moreThis paper presents a methodology for estimating the incident duration and identifying its critical contributing factors in the state of Maryland. The incident database from Year 2003 to Year 2006 from the Maryland State Highway (MDSHA) and Police Accident Report database were used for model development. This study employed a hybrid model using the Rule-Based Tree Model (RBTM), Multinomial Logit Model (MNL) and Naive Bayesian Classifier (NBC) to develop the primary estimation model. Through this model development a number of remarkable findings regarding relationships between the set of key factors and incident duration were found. The proposed model along with findings will play a vital role to establish an advanced traveler information system that can provide the incident-induced delay to the en-route drivers.

Abstract

Providing better information to the public is an important way to improve the transportation system. There is, however, a gap in the quality of the information of current transportation information systems. Inspired by the ubiquitous wireless communication network, the Co...Lead moreProviding better information to the public is an important way to improve the transportation system. There is, however, a gap in the quality of the information of current transportation information systems. Inspired by the ubiquitous wireless communication network, the Connected Traveler project at US-101 corridor, San Francisco Bay area, aims at providing reliable real-time information to the travelers. We briefly outlined the design of the system. Major enabling technologies that help to generate personalized, real-time information with better situation awareness are also introduced, to include the GPS fusing algorithm and a framework of scenario parsing based on the GPS location data. The system is currently under pilot testing and will be launched to the public for a field testing in the first half of 2010.

Abstract

Most transit trip planning systems are based on static schedules and generate trips that are not dynamically responding to delays in transit operation, caused by traffic congestions or accidents. In addition, the park-and-ride travel mode is common in metropolitan areas. ...Lead moreMost transit trip planning systems are based on static schedules and generate trips that are not dynamically responding to delays in transit operation, caused by traffic congestions or accidents. In addition, the park-and-ride travel mode is common in metropolitan areas. However, very few transit trip planners incorporate the real-time transit data and park-and-ride mode. This paper describes a multimodal trip planning system that provides multiple modes: driving, transit and park-and-ride. The system considers the real-time transit arrival time, which is estimated by a prediction model. Our preliminary cast studies show that the multimodal trip planning system works very well.

Abstract

The object of our research is the commercial area of the Ontario-Quebec Continental Gateway and Trade Corridor (OQCGTC) where at less 60% of the Canadian GDP and 70% of the total Canada’s international trade are generated and at less 60% of the Canada’s total population i...Lead moreThe object of our research is the commercial area of the Ontario-Quebec Continental Gateway and Trade Corridor (OQCGTC) where at less 60% of the Canadian GDP and 70% of the total Canada’s international trade are generated and at less 60% of the Canada’s total population is located in this area. In the OQCGTC area, many economical and social problems are developed: Unbalanced modal distribution due to the truck domination; congestion problems and the wear of the infrastructure, spatially in the hub-and spokes and the boarders; lack in safety, in security; and decrease of the quality of life. In our research, we try to identify some several solutions to these problems by applying a Benefit-Cost Analysis (BCA) on the transportation network of the OQCGTC, from which, some suitable ITS solutions will be proposed. Key words: Transportation, ITS, Benefit-Cost Analysis, BCA, Continental Gateway, Ontario- Quebec Corridor, Advanced Fleet Management Systems, Commercial Vehicle Operations, CVO.

Abstract

Transit agencies have the opportunity to improve the delivery of services by using data from ITS technologies. Different ITS technologies and datasets are currently being used by transit agencies for different purposes. However, there is still the need for more sophistica...Lead moreTransit agencies have the opportunity to improve the delivery of services by using data from ITS technologies. Different ITS technologies and datasets are currently being used by transit agencies for different purposes. However, there is still the need for more sophisticated software applications to leverage the value of current ITS technologies. On-time performance is an important measure to almost every transit agency. Yet, there are still missing opportunities for improving on-time performance. This paper presents a method for monitoring on-time performance real time. It uses Automatic Vehicle Location (AVL) data and a web service that publishes a dataset directly from the database. An extended service is also included for system administrators. The paper describes the methodologies used to set up the data management, reporting services, web service, web application, and Skype software technology, which is used to process requests and to make the phone calls. This system can be used to notify transit staff automatically when the on-time performance for the whole system or a particular route is below a desired threshold. A case study conducted using data from Miami-Dade Transit (MDT) is also presented in this paper. It is expected that the methodology used and the findings from this research can be applied by transit agencies to help improve operational efficiencies and quality of service.

Abstract

The concierge service model is a new value-added service in the Location-Based Services (LBS) market, designed to provide users with integrated information on transportation and Points-Of- Interest (POI) to support smarter decision regarding route choice. The Concierge Se...Lead moreThe concierge service model is a new value-added service in the Location-Based Services (LBS) market, designed to provide users with integrated information on transportation and Points-Of- Interest (POI) to support smarter decision regarding route choice. The Concierge Service Problem is to find a route and location of POIs between an origin and a destination with minimum total cost including the purchasing and travel cost. To respond to a user’s query for such a service, a solution algorithm should be both efficient and accurate enough to maintain serviceability and commerciality. The dynamic programming (DP) methods are developed to find the exact solutions for given problems. DP can lessen the complexity of the problem and suggested adaptive method reduces the response time significantly. For a case that multiple optional routes are preferable, a method that finds second or third optimal solution is also introduced. These solution methods are implemented using the Chicago and Seoul metropolitan network. Test results show those dynamic programming methods can solve the large size problems within minutes.

Abstract

Speed variation is closely related to traffic crash occurrence. Thus, speed management strategies reducing speed variation is expected to reduce crash frequency, not only improving safety but also preventing congestion due to crash occurrence. This study was to develop a ...Lead moreSpeed variation is closely related to traffic crash occurrence. Thus, speed management strategies reducing speed variation is expected to reduce crash frequency, not only improving safety but also preventing congestion due to crash occurrence. This study was to develop a modeling approach of identifying promising road segments for safety improvement through such speed management strategies and to illustrate how to select segments based on the model results. By applying three statistical methods (generalized additive model, negative binomial model, and empirical Bayes method) to data collected on 190-kilometer expressway section in Korea, the study was able to develop empirical models for selecting promising segments for safety improvement by the speed management strategies and to generate top 10 promising segments for implementing the strategies.

Abstract

Microscopic traffic simulation models have been widely accepted in the evaluations of new treatments in the surface transportation system. These include new highway, lane usage (e.g., high occupancy vehicle lane or high occupancy toll lane), speed limits (e.g., variable s...Lead moreMicroscopic traffic simulation models have been widely accepted in the evaluations of new treatments in the surface transportation system. These include new highway, lane usage (e.g., high occupancy vehicle lane or high occupancy toll lane), speed limits (e.g., variable speed limit, and uniform or differential speed limits), etc. Additional needs such as considering lateral movements within the lane made researchers develop plug-in modules on the basis of application programming interface (API). With a recent initiation of IntelliDrive or cooperative vehicle infrastructure system, a traffic simulation research community has faced to consider directions for the future microscopic traffic simulation modeling tools. This paper conducted comprehensive assessments on the existing practices in the microscopic simulation modeling and future modeling needs, and recommended that the development of traffic simulation model independent plug-in modules. Additional recommendations including short-term and long-term approaches were discussed.

Abstract

Emerging vehicular safety applications require low delay communications and reliable packet dissemination. Significant developments have taken place over the past few years. IEEE WAVE and ISO CALM have been developed as international standards for ITS applications. Both W...Lead moreEmerging vehicular safety applications require low delay communications and reliable packet dissemination. Significant developments have taken place over the past few years. IEEE WAVE and ISO CALM have been developed as international standards for ITS applications. Both WAVE and CALM support multi-channel operations and use CAMA/CA as channel access mechanism. WAVE can impose a latency of 54 milliseconds for allowing multi-channel operations. CSMA/CA may experience unpredictable delay and packet drop. In this paper, we propose a technique to increase channel coverage and reduce latency for safety messages in multi-channel vehicular environments. We also propose a congestion control protocol for vehicular communication networks that use CSMA/CA channel access mechanism. The proposed scheme guarantees that the life saving alert messages gain channel access while contending with other messages.