Showing papers by "Mashrur Chowdhury published in 2016"

A Review of Communication, Driver Characteristics, and Controls Aspects of Cooperative Adaptive Cruise Control (CACC)

Abstract: Cooperative adaptive cruise control (CACC) systems have the potential to increase traffic throughput by allowing smaller headway between vehicles and moving vehicles safely in a platoon at a harmonized speed. CACC systems have been attracting significant attention from both academia and industry since connectivity between vehicles will become mandatory for new vehicles in the USA in the near future. In this paper, we review three basic and important aspects of CACC systems: communications, driver characteristics, and controls to identify the most challenging issues for their real-world deployment. Different routing protocols that support the data communication requirements between vehicles in the CACC platoon are reviewed. Promising and suitable protocols are identified. Driver characteristics related issues, such as how to keep drivers engaged in driving tasks during CACC operations, are discussed. To achieve mass acceptance, the control design needs to depict real-world traffic variability such as communication effects, driver behavior, and traffic composition. Thus, this paper also discusses the issues that existing CACC control modules face when considering close to ideal driving conditions.

Vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication in a heterogeneous wireless network – Performance evaluation

Abstract: Connected Vehicle Technology (CVT) requires wireless data transmission between vehicles (V2V), and vehicle-to-infrastructure (V2I). Evaluating the performance of different network options for V2V and V2I communication that ensure optimal utilization of resources is a prerequisite when designing and developing robust wireless networks for CVT applications. Though dedicated short range communication (DSRC) has been considered as the primary communication option for CVT safety applications, the use of other wireless technologies (e.g., Wi-Fi, LTE, WiMAX) allow longer range communications and throughput requirements that could not be supported by DSRC alone. Further, the use of other wireless technology potentially reduces the need for costly DSRC infrastructure. In this research, the authors evaluated the performance of Het-Net consisting of Wi-Fi, DSRC and LTE technologies for V2V and V2I communications. An application layer handoff method was developed to enable Het-Net communication for two CVT applications: traffic data collection, and forward collision warning. The handoff method ensures the optimal utilization of available communication options (i.e., eliminate the need of using multiple communication options at the same time) and corresponding backhaul communication infrastructure depending on the connected vehicle application requirements. Field studies conducted in this research demonstrated that the use of Het-Net broadened the range and coverage of V2V and V2I communications. The use of the application layer handoff technique to maintain seamless connectivity for CVT applications was also successfully demonstrated and can be adopted in future Het-Net supported connected vehicle applications. A long handoff time was observed when the application switches from LTE to Wi-Fi. The delay is largely due to the time required to activate the 802.11 link and the time required for the vehicle to associate with the RSU (i.e., access point). Modifying the application to implement a soft handoff where a new network is seamlessly connected before breaking from the existing network can greatly reduce (or eliminate) the interruption of network service observed by the application. However, the use of a Het-Net did not compromise the performance of the traffic data collection application as this application does not require very low latency, unlike connected vehicle safety applications. Field tests revealed that the handoff between networks in Het-Net required several seconds (i.e., higher than 200 ms required for safety applications). Thus, Het-Net could not be used to support safety applications that require communication latency less than 200 ms. However, Het-Net could provide additional/supplementary connectivity for safety applications to warn vehicles upstream to take proactive actions to avoid problem locations. To validate and establish the findings from field tests that included a limited number of connected vehicles, ns-3 simulation experiments with a larger number of connected vehicles were conducted involving a DSRC and LTE Het-Net scenario. The latency and packet delivery error trend obtained from ns-3 simulation were found to be similar to the field experiment results.

Integration of Structural Health Monitoring and Intelligent Transportation Systems for Bridge Condition Assessment: Current Status and Future Direction

Abstract: Recent catastrophic bridge failures clearly indicate the urgent need for improving interval-based bridge inspection procedures that are qualitative and subjective in nature. Structural Health Monitoring (SHM) can mitigate the deficiencies of interval-based inspection techniques and provide real-time diagnostic information regarding the bridge structural health. SHM is not flawless however; the variability in the vehicle characteristics and traffic operational conditions makes it prone to false diagnosis. Recent advancements in the integration of SHM with intelligent transportation systems (ITS) demonstrate the successful use of ITS devices (e.g., traffic cameras, traffic detectors) in the analysis of bridge responses to multimodal traffic with varying loads or during the critical events that cause excess vibration beyond the normal limit. In an ITS-informed SHM system, the ITS device collected data can be integrated with SHM to increase the reliability and accuracy of the SHM system. This integration would reduce the possibility of false diagnosis of damages detected by the SHM system (e.g., vibrations caused by heavy vehicles on a bridge could be read by a SHM sensor as a structural health problem of the bridge), which would eventually decrease the bridge maintenance costs. Similarly, in SHM-informed ITS system, SHM sensors can provide data on bridge health condition for ITS applications, where ITS uses this bridge health condition information for real-time traffic management. In this paper, literature related to both ITS-informed SHM and SHM-informed ITS is reviewed. Based on the literature review, potential challenges and future research directions associated with ITS-SHM integration are also discussed.

An Efficient Wireless Power Transfer System to Balance the State of Charge of Electric Vehicles

Abstract: As an alternate form in the road transportationsystem, electric vehicle (EV) can help reduce the fossil-fuelconsumption. However, the usage of EVs is constrained by thelimited capacity of battery. Wireless Power Transfer (WPT) can increase the driving range of EVs by charging EVs inmotionwhen they drive through a wireless charging laneembedded in a road. The amount of power that can be suppliedby a charging lane at a time is limited. A problem here iswhen a large number of EVs pass a charging lane, how toefficiently distribute the power among different penetrationslevels of EVs? However, there has been no previous researchdevoted to tackling this challenge. To handle this challenge, wepropose a system to balance the State of Charge (called BSoC) among the EVs. It consists of three components: i) fog-basedpower distribution architecture, ii) power scheduling model, and iii) efficient vehicle-to-fog communication protocol. The fogcomputing center collects information from EVs and schedulesthe power distribution. We use fog closer to vehicles ratherthan cloud in order to reduce the communication latency. Thepower scheduling model schedules the power allocated to eachEV. In order to avoid network congestion between EVs and thefog, we let vehicles choose their own communication channelto communicate with local controllers. Finally, we evaluateour system using extensive simulation studies in NetworkSimulator-3, MatLab, and Simulation for Urban MObilitytools, and the experimental results confirm the efficiency ofour system.

Intelligent Transportation Systems-A Frontier for Breaking Boundaries of Traditional Academic Engineering Disciplines [Education]

Abstract: Introduction The evolution of the modern transportation system has been instrumental in the prosperity of human civilization. Over the centuries, technological innovations have improved the performance and efficiency of transportation systems, which has in turn led us to the creation of the modern intelligent transportation system (ITS). Nonetheless, innovations in sensing, computing, analytics and communication technologies over the last few decades have vastly changed how we consume transportation services. According to the US National Academy of Engineering's report "The Engineer of 2020: Visions of Engineering in the New Century," information and communication technologies will be integrated in every process and structure in future, and these technologies will be critical to the seamless performance of every engineered product [1]. Auto makers are expected to market several vehicle models with vehicle-tovehicle (V2V) connectivity within a few years with a subsequent presence of autonomous vehicles on highways within a decade. Such breakthroughs will create new challenges for ITS professionals concerning the design and development of ITS infrastructure. Although multidisciplinary skills are essential for ITS professionals, the current pedagogy of training ITS engineers is inadequate for this new era of smart and connected transportation systems. Consequently, there is a great urgency to train a new generation of mobility professionals in traditional traffic engineering skills as well in cyberphysical systems. The focus of this article is to establish the importance of a new educational focus area in ITS at the undergraduate and graduate levels.

Connectivity supported dynamic routing of electric vehicles in an inductively coupled power transfer environment

Abstract: Electric vehicle (EV) charging problem impedes its wide scale commercial adoption. In this study, the authors address this problem through an ant colony optimisation based multiobjective routing algorithm that is dedicated to accommodate EV trips. By using connectivity, EVs communicate with other vehicles and infrastructure components to transmit information in real time for finding the best route, and for intelligently recharging on the move using an inductively coupled power transfer system. Such connected EVs are capable of adapting each trip with the lowest travel time and/or the lowest recharge cost along with an optimal recharge plan to prevent a battery drain. As a case study, a real world roadway network in Charleston, South Carolina was simulated to examine the performance of the routing strategy. Simulation analysis revealed that connected EVs can reduce not only the total travel time and the energy consumption, but also the recharged volume of electricity and corresponding cost, thus significantly relieving the concerns of range anxiety of EV drivers. This routing approach potentially leads to a reduction in the EV battery capacity requirement, which in turn can reduce the cost of energy storage systems to a reasonable level.

Review of State DOTs Policies for Overweight Truck Fees and Relevant Stakeholders’ Perspectives

Abstract: Of all roadway vehicles, trucks inflict the greatest deterioration to pavements and bridges owing to their heavy gross weights and axle loads. States issue permits to trucks beyond legal weight limits and collect fees to compensate for additional damage. To study the extent to which state departments of transportation (DOTs) have allowed passage of overweight loads, the first objective of this paper was to characterize overweight load permit practices among all U.S. states, and the second objective was to identify stakeholders’ perspectives on how to modernize current overweight permit practices. Through an analysis of existing fee policies, this research has characterized the state of the practice in permit fees for overweight loads on public roadways, and evaluated these practices. The subsequent data showed a wide array of policies on overweight permitting, such that a single interstate overweight freight trip might encounter several diverse overweight permitting policies. Although the range of...

The Impact of Traffic Incident Locations on a Metropolitan Evacuation

Abstract: Modeling emergency evacuations can help engineers, planners, and emergency managers identify the approximate time it would take for evacueesto leave a disaster area Unfortunately, many evacuation studies do not account for traffic incidents This study examined the effect of traffic incidents during a no notice emergency evacuation in the eastern St Louis metropolitan area road network The roadway network was modeled using traffic micro-simulation software VISSIM, which utilized the expected traffic volumes that were determined by the regional planning agency, and guided by input from the transportation engineers at the Illinois Department of Transportation (IDOT) Because traffic speeds are expected to be low during such a high-volume event, this study considered only minor incidents Incident locations were selected based on historical data The results suggest that minor traffic incidents occurring upstream of key bottlenecks created no significant change in delay or evacuation duration On the contrary, minor traffic incidents downstream of bottlenecks can significantly increase delay; albeit not enough to delay the duration of the entire evacuation by more than 15 minutes Thus, during no notice emergency evacuations, traffic managers could prioritize available traffic incident management resources accordingly Keywords: Evacuation, Traffic incidents, Traffic simulation Copyright c 2016 SERSC Language: en

Safety Analysis of Driveway Characteristics Along Major Urban Arterial Corridors in South Carolina

Abstract: In April, 2013, the South Carolina Department of Transportation (SCDOT) initiated research to improve driveway safety and enhance access management practices in South Carolina. The intent of the study was to determine the potential safety and operational consequences of individual driveways and their specific characteristics, so that informed decisions can be made when granting or denying a particular access point permit application. The researchers examined current and historical practices used by other transportation agencies with regard to access management. A comprehensive driveway database was developed using empirical data collected along several corridors that was used to rank driveway related crashes from highest to lowest frequency. The researchers used this database to statistically analyze and identify the correlation of access issues with crash data from 2012. Crash data were associated with driveways using complex Geographic Information System (GIS) modeling tools. A new South Carolina Collision and Ticket Tracking System (SCCATTS) has enhanced crash location data significantly, and was found to be a critical component for correctly associating crashes with driveways. The statistical analysis identified several significant independent variables that influence crash rates either positively or negatively. The results indicate that increasing the distance between driveways, increasing the number of entry lanes, and having a raised median will decrease driveway related crashes. Conversely, increasing driveway width, corridor volume and corridor speed limit will increase crashes. Similarly, a driveway with high turnover land use, a driveway with full access (as opposed to right-in right-out), and the presence of nearby signalized intersections will increase frequency of crashes. The statistical analysis was used to develop crash modification factors for different driveway characteristics.

Connected Vehicle Technology for Allowing Priority Requests at Signalized Intersections - An Analysis

Abstract: This research used microscopic simulation to evaluate operational performance and feasibility of signal priority for connected vehicles (CV) at a signalized intersection. CVs with signal priority were simulated with penetration levels ranging from 10% to 100% as well as with various combinations of directions being allowed to request priority. These scenarios were compared to optimized signal timings without any priority to determine the effectiveness of the system in terms of average delay. It was discovered that CV with signal priority experienced less delay than non-CV for all priority direction scenarios studied up to a certain penetration level. When all directions and major street movements in both directions are allowed to request priority, the advantage for CVs was statistically significant up to 20% CV penetration. When priority was only allowed to be requested in the direction of highest flow, CVs experienced lower delay at a statistically significant level up to 40% CV penetration levels. A benefit-cost analysis was performed for the scenario where CV traveling in the direction of highest flow considering that CV owners may pay for priority to reduce delay to determine the viability of this type of system. The benefit-cost analysis considered the revenue generated from CVs requesting priority at intersections and the system deployment cost, and resulted in a benefit-cost ratio greater than 1 at as low as 20% CV penetration levels. Benefit-cost ratios as high as 3 were observed at 10% CV penetration level when the benefit of decreased network delay for all vehicles was included.

Process for Developing Asynchronous Online Training for Transportation Agency Professionals

Abstract: Efficient training is an essential component of work force development for transportation agencies. The South Carolina Department of Transportation (DOT) recognized one such training need in its management of contracts for professional services consultants. This recognition led to a research effort to identify standardized procedures in the procurement and administration of these contracts, resulting in the development of a training manual and daylong pilot training session. Although the session received positive feedback, it limited the time and location for delivery. This traditional, in-class method is no longer the only available option. Asynchronous online training presents agencies with the option of providing training to employees regardless of their spatial or schedule variabilities while minimizing the need for instructor effort and availability. In light of this change, the South Carolina DOT commissioned a subsequent research effort to study best practices for development, delivery, and assessm...