Browsing by Subject "Variable message signs"

Now showing 1 - 7 of 7
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    Comparison of Dual-Phase and Static Changeable Message Signs to Convey Airline Information on Interstate Freeways
    (Minnesota Department of Transportation Research Services Section, 2010-01) Harder, Kathleen A.; Bloomfield, John R.
    We used a fully interactive PC-based STISIM driving simulator to compare dual-phase Changeable Message Signs (CMSs) and static CMSs. The participants were 120 licensed drivers from three age groups: 18-24, 32-47, and 55- 65 years of age. They drove eleven miles on a simulated six-lane highway towards an airport, knowing which airline to look for. Airline information was provided on two separate CMSs located 500 ft (152.4 m) apart on the highway in one condition, or on a single dual-phase CMS in the other condition. The participants took the correct exit on 89.6% of the drives (215 of 240). There were no statistically significant differences between the number of participants who failed to take the correct exit in the dual-phase and the static CMS conditions. On the approach to the CMSs displaying airline information, there were significant differences in average speed between the three age groups—younger drivers drove faster than middle age and older drivers. However, average speeds were not different in the dual-phase and static CMS conditions. Some individuals reduced speed on approaching the CMSs—suggesting similar reductions could occur in real world driving in free flow conditions. There were no differences in the number or magnitude of the speed reductions for the dual-phase and static CMS conditions. In this experiment, displaying airline information on a single dual-phase CMS was as effective in influencing driving behavior as displaying the same airline information on two static CMSs.
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    Counting Empty Parking Spots at Truck Stops Using Computer Vision
    (Center for Transportation Studies, 2011-05) Pushkar, Modi; Vassilios, Morellas; Papanikolopoulos, Nikolaos
    For at least the past decade, truck driver fatigue has been thought to be a contributing factor in a number of heavy truck accidents. For better utilization of truck stops and to provide truck drivers with safe rest options, we are designing an automated truck stop management system that can compute occupancy rates at stops and notify drivers about the availability of parking spots using variable message displays located about 30 or 40 miles before the stop. Our system detects, classifies and localizes vehicles on the truck stop's grounds by using a set of video cameras, from which video frames are analyzed in real-time.
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    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. Imran
    The 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.
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    The Effectiveness and Safety of Traffic and Non-Traffic Related Messages Presented on Changeable Message Signs—Phase II
    (Minnesota Department of Transportation, 2008-08) Harder, Kathleen A.; Bloomfield, John R.
    In Phase II of this investigation, we used a fully interactive PC-based STISIM driving simulator, to conduct two experiments which were similar to experiments in Phase I. The participants were 120 licensed drivers from three age groups—18-24, 32-47, and 55-65 years old—who drove, in free flow traffic, for approximately 20 miles on a four-lane freeway before encountering target messages on Changeable Message Signs (CMSs). The Phase II CMS messages were clearer and less complex than those used in Phase I. In the first experiment the target message was changed to “Road Closed/Crash Ahead/Use Thompson Exit:” 93.3% of the participants took the exit—as compared to 55.8% in Phase I. In the second experiment, the message was changed to “Abducted Child/Tune To/Radio 88.5 FM:” 71.7% of the participants (71.7%) could remember enough information to enable them tune to 88.5 FM—as compared to 8.3% who could recall some vehicle information and at least five license plate letters and numbers from the Phase I CMS (“AMBER Alert/Red Ford Truck/ MN Lic# SLM 509”). Some participants reduced speed on approaching the CMSs, suggesting similar reductions could occur in real world driving in free flow conditions. However, when traffic is congested speeds are typically slower, and drivers are less likely to reduce speed still further to read CMSs. We conducted a survey which showed drivers think it is very useful to have information about traffic problems and roadway maintenance schedules on CMSs. Also, we analyzed real-world traffic speed data obtained when CMS messages were deployed. Finally, we conducted observations at Mn/DOT’s Regional Transportation Management Center (RTMC), focusing on the decision-making processes involved when traffic-related CMS messages are deployed.
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    Evaluation of the Smart Work Zone Speed Notification System
    (Minnesota Department of Transportation., 2019-06) Hourdos, John; Parikh, Gordon; Dirks, Peter; Lehrke, Derek; Lukashin, Pavel
    The Smart Work Zone Speed Notification (SWZSN) system aims to alleviate congestion, queuing, and rear end crashes in work zones by informing drivers of the speed of the downstream segment using a type of portable Intelligent Lane Control System (ILCS), Portable Changeable Message Signs (PCMS). The hypothesis was that drivers, knowing the speed up to 1 mile downstream, will slow down early or at least be alert and perform smoother decelerations. Video of the SWZSN was analyzed over two years of operation by the Minnesota Traffic Observatory. Overall, the system resulted in beneficial reductions of selected decelerations by the drivers. In situations where the messages communicated to the drivers were consistent and accurate, reductions of more than 30% in the selected deceleration rates were observed. Unfortunately, there were several cases where counterproductive or misleading messages were communicated to the drivers, prompting relative increases to the selected deceleration rates. The most important observation, stemming from both positive and negative influences, was that the speed notification system was noticed by drivers and resulted in a statistically significant influence on driving behavior, unlike other driver alert systems.
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    Minnesota Department of Transportation Rural Intersection Conflict Warning System (RICWS) Reliability Evaluation
    (Center for Transportation Studies, University of Minnesota, 2014-06) Menon, Arvind; Donath, Max
    The Minnesota Department of Transportation (MnDOT) developed the Rural Intersection Conflict Warning System (RICWS) Deployment project to reduce crashes at stop-controlled intersections. It is a statewide, Intelligent Transportation Systems project that will deploy intersection conflict warning systems at up to 50 rural, stop-controlled intersections. These systems will address crashes at stop-controlled intersections by providing drivers - on both the major and minor road - with a dynamic warning of other vehicles approaching the intersection. The first RICWS site, Trunk Highway 7 and Carver County CSAH 33, was evaluated for a period of 34 days to demonstrate the reliability of the system. During this period, the RICWS signs, beacons, and any other displays were covered and unavailable for driver interaction. The University of Minnesota installed a portable Intersection Surveillance System (ISS) and collected data from the RICWS as well as from the ISS. The data collected from the RICWS was validated against data recorded by the ISS in order to determine the accuracy and reliability of the RICWS. The RICWS was determined to have an activation rate of 99.98%, and meets the MnDOT specification of 99.95% sign activation rate. Sign activations were also validated using video captured at the site and a sample of times for valid activations and valid periods when the sign was inactive were recorded.
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    Visual Warning System for Worker Safety on Roadside Workzones
    (Minnesota Department of Transportation, 2016-08) Banaeiyan, Nazanin; uz Zaman, Attiq; Hayee, M.Imran
    Growing 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.