1,721,013 research outputs found
Framework and Guidelines for the Development of a Twin Cities Mesoscopic DTA Model
Full text linkLarge-scale Mesoscopic traffic simulation is a newly adopted tool due to recent advancements in traffic modeling as well as computer hardware. New studies show that modeling on a scale necessary to answer complicated questions such as diversion patterns around multi-corridor work zones is feasible. As with many research projects, the original objective of this project was adjusted to maximize the benefit from the final product. The initial objective was to create a framework and guidelines for the development of a Twin Cites Mesoscopic Dynamic Traffic Assignment (DTA) model. Discoveries during the course of the project as well as MnDOT priorities and urgent needs directed the project away from the development of guidelines and more toward the proof-of-concept and the development of the foundation for such a metro-wide model. In addition, a parallel MnDOT project, undertaken by a consulting group using the DynusT application, developed an almost metro-wide model. The project described in this report, changed its scope to treat this parallel project as a case study and identify its future utility beyond its immediate goals, which were to determine the most cost-effective construction phasing for several projects during the 2017-2020 construction seasons.Lehrke, Derek; Hourdos, John. (2017). Framework and Guidelines for the Development of a Twin Cities Mesoscopic DTA Model. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/188993
How Locals Need to Prepare for the Future of V2V/V2I Connected Vehicles
Full text linkConnected 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.Parikh, Gordon; Duhn, Melissa; Hourdos, John. (2019). How Locals Need to Prepare for the Future of V2V/V2I Connected Vehicles. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/208698
Implementation of High Accuracy Radar Detectors for Traffic Safety Countermeasure Evaluation
Full text linkRural roadways account for a significant portion of fatal crashes in the United States despite carrying lower total vehicle miles traveled than urban roads. An important contributor to this is excessive speeds at horizontal and vertical curves. While geometric design has established norms for handling these curves, the message is still often difficult to communicate to drivers. Recent technologies have been developed to enhance this communication on horizontal curves; however, treatments for vertical curves have not yet experienced similar advancements. A new approach, involving chevron signs, is being considered by Washington County, Minnesota. To accurately assess the impact of these signs on driver behavior, a before-after study must be implemented on one or more vertical curve locations. Given that such a study must reflect driver reactions to roadway messages, detailed vehicle trajectories must be collected. To capture speed trajectories of vehicles traversing vertical curves, the Minnesota Traffic Observatory developed radar-based, data-collection stations. These stations use automotive radar devices along with custom recording equipment and battery power mounted in weatherized cases to quickly and easily collect vehicle trajectory data for analysis. Through control-vehicle passes and instantaneous radar gun measurements, these stations have been shown to reliably measure the speed and position of vehicles traversing a vertical curve. With the two stations developed, a full field implementation could be developed to collect trajectories for analysis both before and after implementation of a new traffic-control device. For larger-scale implementations of these systems, the methodologies in this report could be used for capturing and post-processing of vehicle trajectories, although additional tools for cleaning and analyzing multiple simultaneous vehicle trajectories would be advised.Parikh, Gordon; Hourdos, John. (2014). Implementation of High Accuracy Radar Detectors for Traffic Safety Countermeasure Evaluation. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/164688
Technology in Planning and Participatory Processes: Identifying New Synergies through Real World Application
No full textThis report provides a discussion of findings from a study of the application of planning support systems (PSS) to typical participatory processes. For the purposes of this study, we are inclusive in our definition of planning support systems, addressing all types of technology that might be used in the preparation, execution, and analysis of participatory planning processes and outcomes. The overall intent of the study is to develop an understanding of how to tailor technologies to the unique aspects of various types of participation efforts used in planning practice. The report outlines some important background information related to the use of various types of technologies in participatory processes, including the challenges and opportunities associated with their use. The report also highlights and categorizes a range of current technologies that can be used to supplement or enhance planning and participatory processes. In addition, the report summarizes the findings of a series of five focus groups conducted with planners, engineers, and other practitioners related to participation processes and the application of technology. Finally, the report concludes with a discussion of the findings of survey or practitioners related to their perceptions of constraints and opportunities related to the implementation of technology in planning and participatory processes in their organizations.Schively Slotterback, Carissa; Hourdos, John. (2009). Technology in Planning and Participatory Processes: Identifying New Synergies through Real World Application. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/97578
Evaluation of a Central Traffic Signal System and Best Practices for Implementation
Full text linkDetailed Intersection Control Information (ICI), including timing, phasing, geometric, and demand attributes, is an increasingly important resource for researchers, consultants, and private sector companies for many applications, including development of traffic models and technologies such as vehicle information or automation systems. While this information has historically been difficult to distribute due to variations in the availability and format across the numerous jurisdictions that operate signals, recent trends toward increased use of Central Traffic Signal Control Systems (CTSCSs) have made creation of a unified, standardized system for organizing ICI more feasible. To help work toward this, in this project researchers interviewed and surveyed signal operation engineers and transportation modelers throughout Minnesota to learn how different jurisdictions manage information relating to their signals and how this information is used for operations and planning. With this information, researchers developed a comprehensive Unified Set of Intersection Control Information (U-ICI) that contains all the information required to describe the control of an intersection in a format that is readable by both humans and machines. Along with this, researchers evaluated the availability of this information and the feasibility of using existing CTSCS applications to store this information. While the researchers conclude that it is not feasible to use these applications to store all of the U-ICI, the applications will likely make the process of implementing and populating such a system easier. Though some information may be contained in formats that will require manual effort to digitize, the up-front effort to do so will be a worthwhile pursuit.Parikh, Gordon; Hourdos, John. (2019). Evaluation of a Central Traffic Signal System and Best Practices for Implementation. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/204688
Flagger Operations: Investigating Their Effectiveness in Capturing Driver Attention
Full text linkThis two-pronged (driving simulation and field study) investigation of driver behavior in work zones contributes basic and applied knowledge to our understanding of work zone safety. In the driving simulator study, a fully interactive PC-based STISIM driving simulator was used to test the effectiveness of roadway elements designed to capture and sustain the attention of drivers in flagger-operated work zones. The participants were 160 licensed drivers from four age groups: 18-24, 32-47, 55-65, and 70+ years of age. Each participant drove each of the three conditions in counterbalanced order. The driving simulator study revealed that the new set of elements is more effective than the elements currently used to reduce driving speeds on the approach to a flagger-controlled work zone. No difference in mean driver speed was found in response to the sign with an LED presence. The dynamic speed display coupled with the horn is more effective than the dynamic speed display alone. The cognitively engaging elements identified as effective in the driving simulator study were tested in two field operational tests. The field tests revealed that all but one of the elements identified in the experimental driving simulator study were effective. In particular, the findings revealed that a combination of the speed trailer and horn barrel are effective in reducing the overall speed of vehicles approaching the field study work zone. The field test revealed that the new experimental layout practically eliminated high-speed outliers in addition to its success in reducing driver approach speed to the flag operator.Harder, Kathleen; Hourdos, John. (2017). Flagger Operations: Investigating Their Effectiveness in Capturing Driver Attention. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/188994
Evaluation and Improvement of the Stratified Ramp Metering Algorithm Through Microscopic Simulation - Phase II
No full textA new ramp metering strategy implemented on the Twin Cities freeway system to reduce ramp waiting times was evaluated through microsimulation of freeway activity. The study compared Stratified Ramp Metering strategy with the previous Zone Metering Strategy and with no control strategy. Comparison with Zone, which was designed to favor freeway flow, showed the new strategy succeeded in greatly reducing ramp delays and lines. When compared to the results of no control strategy, it reduces freeway travel time, increases freeway speed, smoothes the flow of traffic, and reduces the number of stops. However, travel time, fuel consumption and pollutant emissions are unpredictable under the newer system. Compared to no control strategy, such measures of effectiveness may improve or worsen depending on the freeway patterns and demand. Based on these findings, the researchers will seek improvements to the design of the Stratified Ramp Metering algorithm so as to factor in disruptive traffic patterns.GuidestarMichalopoulos, Panos; Xin, Wuping; Hourdos, John. (2005). Evaluation and Improvement of the Stratified Ramp Metering Algorithm Through Microscopic Simulation - Phase II. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/1014
Streamlining of the Traffic Modeling Process for Implementation in the Twin Cities Freeway Network - Phase II
No full textComprehensive methodologies are proposed for improving the quality of both freeway and arterial intersections traffic volumes for the purpose of enabling and improving traffic simulations. Specifically, established and enhanced procedures for checking and correcting freeway temporal errors are integrated with an optimization-based algorithm for reconciling spatial inconsistencies in freeway traffic counts. In addition to this, an empirical methodology is further integrated to balance arterial intersection traffic counts. The proposed methodologies have been successfully automated and implemented as two computer programs, i.e., TradaX for processing freeway volume and ArtBaT for arterial intersection traffic counts. Initial evaluations of these tools suggest that they have the potential of reducing total modeling time by 25% ~ 30%, while resulting in improved calibration of simulation models, more reliable analysis, and better use of staff resources for meeting project deadlines.Xin, Wuping; Hourdos, John; Michalopoulos, Panos. (2006). Streamlining of the Traffic Modeling Process for Implementation in the Twin Cities Freeway Network - Phase II. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/648
Evaluation of the Effectiveness of ATM Messages Used During Incidents
No full textThis project investigated the use of Intelligent Lane Control Signs based Active Traffic Management for Incident Management on a heavily traveled urban freeway. The subject of the research was the ILCS system on I-94 westbound in downtown Minneapolis. This location was selected because of the frequency of capacity reducing incidents occurring in this freeway segment. This research aimed to evaluate and quantify the effect the system has on drivers, specifically on inducing/directing a desirable lane selection behavior. The strength of various uses of the tool in managing traffic during incidents is explored instead of a general level of success in improving traffic. To achieve this goal, the centerpiece of this research was the comparison and modeling of the lane change rates under different strategies. This was a difficult task because all lane changes in the target freeway section had to be detected and geolocated. The research followed two main thrusts. The first was a detailed analysis of 28 incident events selected among approximately 481 events on record between 2012 and 2013. The second thrust was a statistical analysis testing a number of hypotheses prompted by questions proposed by the project Technical Advisory Panel. In general, it can be concluded that the use of ILCS for incident management has a significant effect on driver behavior and specifically in prompting proper lane selection under capacity reducing incidents.Rindels, Max; Zitzow, Stephen; Hourdos, John. (2016). Evaluation of the Effectiveness of ATM Messages Used During Incidents. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/178993
Enhanced Micro-Simulation Models for Accurate Safety Assessment of Traffic Management ITS Solutions
No full textMuch research has been conducted in the development, implementation, and evaluation of innovative ITS technologies aiming to improve traffic operations and driving safety. Existing micro-simulation modeling only describes normative car-following behaviors devoid of weakness and risks associated with real-life everyday driving. This research aims to develop a new behavioral car-following model that is pertinent to the true nature of everyday human driving. Unlike traditional car-following models that deliberately prohibit vehicle collisions, this new model builds upon multi-disciplinary findings explicitly taking into account perceptual thresholds, judgment errors, anisotropy of reaction times and driver inattention, in order to replicate “less-than-perfect” driving behavior with all its weakness and risks. Most importantly, all parameters of this model have direct physical meaning; this ensures vehicle collisions are replicated as a result of behavioral patterns rather than simply being numerical artifacts of the model. Meanwhile, vehicle trajectories were extracted from real-life crashes collected from a freeway section of I-94WB This is by far the first data collection efforts that aim to collect vehicle trajectories from real-life crashes to aid car-following modeling. These data were employed in this study to test, calibrate and validate the model. This new model is successful in replicating these vehicle trajectories as well as crashes.Xin, Wuping; Hourdos, John; Michalopoulos, Panos. (2008). Enhanced Micro-Simulation Models for Accurate Safety Assessment of Traffic Management ITS Solutions. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/96707
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