Browsing by Subject "Traffic simulation"

Now showing 1 - 6 of 6
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    Access to Destinations: Twin Cities Metro-wide Traffic Micro-simulation Feasibility Investigation
    (Minnesota Department of Transportation, 2008-05) Hourdos, John; Michalopoulos, Panos
    The economic importance of effective traffic management becomes more and more evident as traffic demands increase. Faced with the negative effects of traffic congestion including higher transport costs, greater energy consumption, and increased driver delays, transportation agencies around the world areas have responded by building new roads and enhancing their traffic management systems. However, the high costs associated with these projects, and the possibility that improvements in different parts of a complex traffic management system may give rise to unforeseen interactions, have prompted many metropolitan areas to invest in the creation of metro-wide simulation systems that support the evaluation of alternative traffic management scenarios across an entire traffic network. Such undertakings are far from simple; even small-scale microscopic simulations require large amounts of high-quality data. The objectives of this project were to evaluate the feasibility of developing a traffic simulation system for the Minneapolis-St. Paul metropolitan area, and to propose the most appropriate methodology for the design and implementation of such a system, taking into account local needs and capabilities.
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    Development of Next Generation Simulation Models for the Twin Cities Freeway Metro-Wide Simulation Model—Phase 1
    (Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-10) Hourdos, John
    The collapse of the Interstate 35W Highway Bridge over the Mississippi River in Minneapolis resulted in unexpected loss of life and had serious consequences on mobility and accessibility in the Twin Cities metropolitan area. In response to the network disruption caused by the bridge collapse, a number of traffic restoration projects were proposed and implemented by MnDOT in a very short order. Selection and prioritization of these projects, however, was mainly based on engineering judgment and experience. The only decision-support tool available to traffic engineers was the regional transportation planning model, which is static in nature and decennial. Although such a model is suitable for the evaluation of long-term (in the order of 5 years or longer) transportation investments, it is not appropriate or adequate for short-term (within days or weeks) operational planning in response to a disaster or other emergencies. This was the driving force behind the creation of a comprehensive model of the Twin Cities freeway and major highway system that can support higher levels of traffic simulation resolution. Phase 1, described in this report, of the development of the Twin Cities metro-wide freeway microscopic model covered the importation of the roadway geometry into a microscopic simulator, generation of demand information for the entire model as well as for the calibration of as many as possible individual segments. In total, 1,199 directional kilometers of freeway mainline where included in the model. Including ramps and major highways, the number rises to 2,492 directional kilometers. The demand in the model is generated from 859 zones extracted from the regional planning model.
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    Enhanced Micro-Simulation Models for Accurate Safety Assessment of Traffic Management ITS Solutions
    (University of Minnesota Center for Transportation Studies, 2008-11) Xin, Wuping; Hourdos, John; Michalopoulos, Panos
    Much 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.
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    Evaluating Twin Cities Transitways’ Performance and their Interaction with Traffic on Neighboring Major Roads
    (Center for Transportation Studies, University of Minnesota, 2015-03) Hourdos, John; Lehrke, Derek
    Long-term, regional travel demand models are essential tools used by planning organizations for resource management, project scheduling, and impact studies. Developed primarily at the macroscopic level, these tools lack sufficient detail to capture the influence of local geometry, dynamic traffic controls, or advanced transportation demand management (ATDM) strategies. To bridge the gap, a hybrid mesoscopic-microscopic model was developed. The core of the model, surrounding two light rail corridors in Minneapolis-Saint Paul, Minnesota, was developed at high resolution for microscopic simulation to capture the interaction between traffic signals, transit systems, and the road network. The remainder of the greater Twin Cities area was implemented based on the Regional Planning Model (RPM) maintained by the Metropolitan Council. Interfacing the Aimsun-based hybrid model with the Cube-based RPM, the Twin Cities Metro Hybrid Simulation was used to iteratively improve mode choice and traffic assignment to achieve a dynamic user equilibrium state. Important lessons were learned regarding the effort required to develop and maintain such a model with implications for future large scale regional modelling.
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    MnPASS Modeling and Pricing Algorithm Enhancement
    (Center for Transportation Studies, University of Minnesota, 2015-05) Hourdos, John; Janson, Michael; Levinson, David; Parikh, Gordon
    While High Occupancy Vehicle (HOV) lanes have been used for decades as a strategy for mitigating congestion, research has shown that they are not always effective. A 2001 study of the I-394 and I-35W HOV lanes in Minnesota found that the HOV lanes were on average underutilized, moving fewer people than the General-Purpose Lanes (GPL) even with the increased number of passengers per vehicle. To address the issue of underuse, in 2003 the Minnesota Legislature authorized the conversion of the I-394 HOV lanes into High-Occupancy Toll (HOT) lanes, named the MnPASS Express Lanes. The MnPASS lanes operate using a fully dynamic pricing schedule, where pricing is dictated by the level of congestion in the HOT lane. To better understand the nature of HOT lanes and the decisions of their users, this study explored the possibilities for a microscopic traffic simulation-based model of HOT lanes. Based on a series of field studies where the price of the toll was changed while observing changes in demand in the HOT lane, models describing the lane choice behavior of MnPASS users were developed and calibrated. These models interfaced with the traffic simulation software Aimsun through a number of extension modules and tested on the two MnPASS corridors of I-394 and I35W corridors in the west and south suburbs of Minneapolis, Minnesota. The integrated HOT simulation tool was also used to develop and test a number of alternative pricing strategies including a more efficient version of the current strategy.
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    University of Minnesota Traffic Simulation Study, Washington Avenue Corridor
    (University of Minnesota and BRW Inc., 1997-07-17) BRW Inc.
    This report documents the results of the analysis conducted to address several issues resulting from March 12, 1997 and April 8, 1997 meetings regarding the Washington Avenue Corridor traffic simulation study. Identified issues for further analysis in order to complete the corridor study included the impact of a pedestrian scramble on traffic, the impact of adding a northbound right-turn lane, documenting accident history on Washington Avenue, reviewing shoulder guidelines, and increasing signal timing splits. This report presents the overall recommendations based on the results of the study.