Browsing by Subject "Dedicated short range communications"
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Item A Bus Signal Priority System Using Automatic Vehicle Location / Global Position Systems and Wireless Communication Systems(University of Minnesota Center for Transportation Studies, 2008-12) Liao, Chen-Fu; Davis, Gary A.; Iyer, PriyaCurrent signal priority strategies implemented in various US cities mostly utilize sensors to detect buses at a fixed or preset distance away from an intersection. Traditional presence detection systems, ideally designed for emergency vehicles, usually send signal priority request after a preprogrammed time offset as soon as transit vehicles were detected without the consideration of bus readiness. The objective of this study is to integrate the already equipped Global Positioning System/Automated Vehicle Location (GPS/AVL) system on the buses in Minneapolis and develop an adaptive signal priority system that could consider the bus schedule adherence, its number of passengers, location and speed. Buses can communicate with intersection signal controllers using wireless technology to request for signal priority. Similar setup can also be utilized for other transit-related Intelligent Transportation Systems (ITS) applications. The City of Minneapolis recently deployed wireless technology to provide residents, businesses and visitors with wireless broadband access anywhere in the city. Communication with the roadside unit (e.g., traffic controller) for signal priority may be established using the readily available 802.11x WLAN or the Dedicated Short Range Communication (DSRC) 802.11p protocol currently under development for wireless access in vehicular environment. This report documents the development, verification and validation of the embedded signal priority prototype systems, field testing results and limitations of using the City of Minneapolis Wi-Fi network for Transit Signal Priority (TSP).Item Development and Demonstration of a Cost-Effective In-Vehicle Lane Departure and Advanced Curve Speed Warning System(Minnesota Department of Transportation, 2018-12) Faizan, Muhammad; Hussain, Shah; Hayee, M. I.A Lane-Departure Warning System (LDWS) and Advance Curve -Warning System (ACWS) are critical among several Advanced Driver- Assistance Systems (ADAS) functions, having significant potential to reduce crashes. Generally, LDWS us e different image processing or optical s canning techniques to detect a lane departure. Such LDWS have some limitations such as harsh weather or irregular la ne markings can influence their performance. Other LDWS use a GPS receiver with access to digital maps with lane-level resolution to improve the system's efficiency but make the overall system more complex and expensive. In this report, a lane-departure detection method is proposed, which uses a standard GPS receiver to determine the lateral shift of a vehicle by comparing a vehicle’s trajectory to a reference road direction without the need of any digital maps with lane-level resolution. This method only needs road-level information from a standard digital mapping database. Furthermore, the system estimates the road curvature and provides advisory speed for a given curve simultaneously. The field test results show that the proposed system can detect a true lane departure with an accuracy of almost 100%. Although no true lane departure was left undetected, occasional false lane departures were detected about 10% of the time when the vehicle did not actually depart its lane. Furthermore, system always issues the curve warning with an advisory speed at a safe distance well ahead of time.Item Development and Demonstration of an In-Vehicle Lane Departure Warning System Using Standard GPS Technology(Minnesota Department of Transportation, 2021-06) Chowdhury, Shahnewaz; Hossain, Md Touhid; Hayee, M. I.A lane departure warning system (LDWS) has significant potential to reduce crashes on roads. Most existing commercial LDWSs use some kind of image processing techniques with or without Global Positioning System (GPS) technology and/or high-resolution digital maps to detect unintentional lane departures. However, the performance of such systems is compromised in unfavorable weather or road conditions, e.g., fog, snow, or irregular road markings. Previously, we proposed and developed an LDWS using a standard GPS receiver without any high-resolution digital maps. The previously developed LDWS relies on a road reference heading (RRH) of a given road extracted from an open-source, low-resolution mapping database to detect an unintentional lane departure. This method can detect true lane departures accurately but occasionally gives false alarms, i.e., it can issue lane departure warnings even when a vehicle is within its lane. The false alarms occur due to the inaccuracy of how the RRH originated from an inherent lateral error in open-source, low-resolution maps. To overcome this problem, we proposed and developed a novel algorithm to generate an accurate RRH for a given road using a vehicle's past trajectories on that road. The newly developed algorithm that generates an accurate RRH for any given road has been integrated with the previously developed LDWS and extensively evaluated in the field for detection of unintentional lane departures. The field test results showed that the newly developed RRH Generation algorithm significantly improved the performance of the previously developed LDWS by accurately detecting all true lane departures while practically reducing the frequency of false alarms to zero.Item Development and Demonstration of Merge Assist System using Connected Vehicle Technology(Center for Transportation Studies, University of Minnesota, 2019-04) Hussain, Shah; Peng, Zhiyuan; Hayee, M. ImranOne potential area to improve driver safety and traffic mobility is around merge points of two roadways, e.g., at a typical freeway entrance ramp. Due to poor visibility because of weather or complex road infrastructure, on many such entrance ramps, it may become difficult for the driver on the merging/entrance ramp to clearly see the vehicles travelling on the main freeway, making it difficult to merge. A fundamental requirement to facilitate many advance driver assistance systems (ADAS) functions including a merge assist system is to accurately acquire vehicle positioning information. Accurate position information can be obtained using either sensor-based systems (camera-based, radar, lidar) or global navigation satellite systems (GPS, DGPS, RTK). For these systems to work well for practical road and weather conditions, advanced techniques and algorithms are needed, which make the system complex and expensive to implement. In this research project, we propose a merge assist system by acquiring the relative positioning of vehicles using standard GPS receivers and dedicated short-range communication (DSRC) based vehicle-to-vehicle (V2V) communication. The DSRC-equipped vehicles travelling on the main freeway and on the entrance-ramp will periodically communicate their positioning information with each other. Using that information, the relative trajectories, relative lane, and position of all DSRC-equipped vehicles travelling on the main freeway will be calculated and recorded in real time in the vehicle travelling on the entrance ramp. Finally, a merge-time cushion will also be calculated, which could potentially be used to assist the driver of the ramp vehicle to safely merge into the freeway.Item Development and Field Demonstration of DSRC Based V2V-Assisted V2I Traffic Information System for the Work Zone(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-06) Maitipe, Buddhika; Ibrahim, Umair; Hayee, M. ImranThis report describes the architecture, functionality and the field demonstration results of a newly developed DSRC based V2I work zone traffic information system with V2V assistance. The developed system can automatically acquire important work zone travel information, e.g., the travel time (TT) and the starting location of congestion (SLoC), and relay them back to the drivers approaching the congestion site. Such information can help drivers in making informed decisions on route choice and/or preparing for upcoming congestion. Previously, we designed such a system using DSRC based V2I-only communication, which could not handle longer congestion lengths and the message broadcast range was also very limited. Our current system, on the other hand, can achieve much longer broadcast range (up to a few tens of kms), and can handle much longer congestion coverage length (up to a few kms) by incorporating DSRC based V2I communication with V2V assistance. The new system is also portable and uses only one RSU, which can acquire traffic data by engaging the vehicles traveling on the roadside whether within or outside of its direct wireless access range. From the traffic data, it estimates important traffic parameters, i.e., TT and SLoC, and periodically broadcasts them back to the vehicles approaching the congestion well before they enter the congested area. The results from the field demonstration have indicated that new system can adapt to dynamically changing work zone traffic environments and can handle much longer congestion lengths as compared to the previous system using V2I-only communication without V2V assistance.Item Development and Field Demonstration of DSRC-Based V2I Traffic Information System for the Work Zone(2010-12) Maitipe, Buddhika; Hayee, M. ImranThis report describes the architecture, functionality and the field demonstration of a newly developed dedicated short-range communication (DSRC)-based Vehicle to Infrastructure (V2I) communication system for improving traffic efficiency and safety in the work-zone related congestion buildup on US roadways. The goal was to develop a portable system that can be easily deployed at a work zone site to acquire and communicate important travel information, e.g., travel time (TT) and start of congestion (SoC) location to the driver. By providing this information, i.e., SoC location and TT, drivers can make informed decisions on route choice and be prepared for upcoming congestion. The system is composed of a portable road-side unit (RSU) that can engage the on board units (OBUs) of the traveling vehicles using DSRC technology to acquire necessary traffic data (speed, time, and location). From the acquired data, the RSU periodically estimates the SoC location and TT that are broadcast to all vehicles in its coverage range. An OBU receiving the broadcast message calculates the distance to the SoC location. The distance to the SoC location and TT are then relayed to the driver, who can make smart decisions regarding whether to seek an alternate route and when to expect a sudden speed reduction. Results from the field demonstration have shown that the developed system can adapt to changing work-zone environments smoothly under various congestion patterns on the road.Item Development of a Low-Cost Interface between Cell Phone and DSRC-Based Vehicle Unit for Efficient Use of IntelliDrive Infrastructure(2010-11) Roodell, Beau; Hayee, M. ImranIntelligent transportation systems (ITS), a mission of the US Department of Transportation, focuses on intelligent vehicles, intelligent infrastructure and the creation of an intelligent transportation system through integration with and between these two components. Dedicated Short Range Communications (DSRC), a tool approved for licensing by the Federal Communications Commission (FCC) in 2003, promises to partially fulfill this mission. This research proposal intends to utilize DSRC technology to communicate the traffic safety information available at central infrastructure to a driver’s cell phone. The specific objective of this research project is to design, build and demonstrate a wireless communication interface device that can act as a traffic-safety-information transportation agent between the DSRC vehicle radio unit and a Bluetooth-enabled cell phone inside a vehicle. By having this interface device along with the DSRC radio unit in a vehicle as a separate entity or integrated with a DSRC unit, any driver will be able to receive the valuable traffic safety messages on a Bluetooth-enabled cell phone. The prototype was demonstrated successfully in multiple road and traffic scenarios by transmitting the traffic safety messages to the Bluetooth-enabled cell phone. The next step is to show effectiveness of this system in a realistic environment for which a workzone environment has been chosen to relay traffic safety messages to vehicles approaching the workzone.Item Development of Hybrid DSRC-PCMS Information Systems for Snowplow Operations and Work Zones(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2013-02) Ibrahim, Umair; Hayee, M. ImranThe future deployment of dedicated short range communication (DSRC) technology requires that DSRC-based applications are integrated with existing traffic management techniques so that non-DSRC-equipped vehicles at the early stage of DSRC deployment can also reap the potential benefits of DSRC technology. We have successfully developed and field demonstrated a hybrid traffic-information system combining DSRC technology and portable changeable message signs (PCMS) for work zone environment to improve traffic mobility, and thereby, driver safety. The developed system uses DSRC-based V2I and V2V communication to acquire travel safety parameters such as travel time (TT) and starting location of congestion (SLoC), and disseminate these parameters to both DSRC-equipped vehicles and DSRC-equipped PCMSs, which are strategically placed alongside the road. Using the DSRC-PCMS interface designed for this purpose, PCMSs can receive these travel safety parameters from nearby DSRC-equipped vehicles on the road via DSRC-based V2V communication, and display them for the drivers of the vehicles lacking DSRC capability. Such a system can be useful for an early stage of DSRC deployment when the DSRC market penetration is low. Additionally, a rigorous analysis has been conducted to investigate the minimum DSRC market penetration rate needed for successful functionality of the developed system with respect to both acquisition and dissemination of TT and SLoC. Using realistic traffic flow model, guidelines are developed to estimate a minimum DSRC penetration rate needed to deploy the developed system for a variety of traffic scenarios on a given work zone road.Item How Locals Need to Prepare for the Future of V2V/V2I Connected Vehicles(Minnesota Department of Transportation., 2019-08) Parikh, Gordon; Duhn, Melissa; Hourdos, JohnConnected and Automated Vehicles (CAVs) are expected to affect the foundations of transportation operations and roadway maintenance as they become more prevalent on the roadways. This report is an effort to address this complex subject for the various owners, agencies and stakeholders involved in traffic operations. It discusses the connected vehicle ecosystem and its background, potential CAV applications, types of communication and hardware required for CAV systems, and recommendations to local road owners. The report also includes a survey sent to local road owners to assess the current readiness of the transportation system for CAVs. Although it is too early to give specific recommendations, general guidance is provided for road owners to begin preparing for the future of CAVs.Item Visual Warning System for Worker Safety on Roadside Workzones(Minnesota Department of Transportation, 2016-08) Banaeiyan, Nazanin; uz Zaman, Attiq; Hayee, M.ImranGrowing traffic on US roadways and heavy construction machinery on road construction sites pose a critical safety threat to construction workers. This report summarizes the design and development of a worker safety system using Dedicated Short Range Communication (DSRC) to specifically address the workers’ safety for the workers working around the heavy machinery. The proposed system has dual objectives. First objective is to improve workers’ safety by providing visual guidance to the operators of the construction vehicles about the workers’ presence in the vicinity. This visual guidance keeps the operators of the heavy machinery well informed about the whereabouts of the workers in close proximity while operating the heavy vehicle. The second objective of the proposed system is to improve the work-zone traffic mobility by dynamically posting suitable speed limits and other warning messages on the DSRC-equipped variable message signs (VMSs) depending on the workers’ presence in an active work-zone to appropriately warn the drivers of the passing-by vehicles. A prototype was developed and field tests were conducted to demonstrate and evaluate the performance of the proposed system. The evaluation test results show that the system can successfully show the presence of workers around a construction vehicle on an Android tablet with acceptable distance (1.5 – 2 m) and direction (15 – 20 degrees) accuracies. Furthermore, the test results show that a DSRC-equipped VMS can successfully post a suitable speed limit corresponding to the presence of workers in its vicinity.