Download or read book Modal Emissions Modeling with Real Traffic Data written by Jason A. Crawford and published by . This book was released on 1999 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report details the use of a modal emissions model to estimate the relative emissions of CO due to changes in vehicle operating characteristics on urban roadways. The Davis Institute for Transportation Studies Emissions Model (DITSEM) was selected to demonstrate the emissions characteristics of different freeway operating conditions. Instrumented vehicle data collected in Houston, Texas provides a set of operating parameters for which CO emissions are estimated. These estimates are calculated for different times of the day on the same facility to determine the relative emissions levels from a representative vehicle traveling on the freeway. The research team examined 10 samples along three roadways (two freeways, and one arterial). Implausible results were found in data exhibiting high average speeds (>60 mph) where average emissions rates were higher than those on the same roadway under congested conditions. This led to several conclusions of which the most important was that the DITSEM model not be used with samples where the percent of the driving cycle greater than 60 mph 2/sec exceeds 9%. This limit represents the highest value from which the model was derived for this variable. In addition, it is noted that the speed instrumentation was not able to provide sufficient precision for meaningful analysis with the available data.

Download or read book Emission estimation based on traffic models and measurements written by Nikolaos Tsanakas and published by Linköping University Electronic Press. This book was released on 2019-04-24 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic congestion increases travel times, but also results in higher energy usage and vehicular emissions. To evaluate the impact of traffic emissions on environment and human health, the accurate estimation of their rates and location is required. Traffic emission models can be used for estimating emissions, providing emission factors in grams per vehicle and kilometre. Emission factors are defined for specific traffic situations, and traffic data is necessary in order to determine these traffic situations along a traffic network. The required traffic data, which consists of average speed and flow, can be obtained either from traffic models or sensor measurements. In large urban areas, the collection of cross-sectional data from stationary sensors is a costefficient method of deriving traffic data for emission modelling. However, the traditional approaches of extrapolating this data in time and space may not accurately capture the variations of the traffic variables when congestion is high, affecting the emission estimation. Static transportation planning models, commonly used for the evaluation of infrastructure investments and policy changes, constitute an alternative efficient method of estimating the traffic data. Nevertheless, their static nature may result in an inaccurate estimation of dynamic traffic variables, such as the location of congestion, having a direct impact on emission estimation. Congestion is strongly correlated with increased emission rates, and since emissions have location specific effects, the location of congestion becomes a crucial aspect. Therefore, the derivation of traffic data for emission modelling usually relies on the simplified, traditional approaches. The aim of this thesis is to identify, quantify and finally reduce the potential errors that these traditional approaches introduce in an emission estimation analysis. According to our main findings, traditional approaches may be sufficient for analysing pollutants with global effects such as CO2, or for large-scale emission modelling applications such as emission inventories. However, for more temporally and spatially sensitive applications, such as dispersion and exposure modelling, a more detailed approach is needed. In case of cross-sectional measurements, we suggest and evaluate the use of a more detailed, but computationally more expensive, data extrapolation approach. Additionally, considering the inabilities of static models, we propose and evaluate the post-processing of their results, by applying quasi-dynamic network loading.

Download or read book Modeling Mobile Source Emissions written by National Research Council and published by National Academies Press. This book was released on 2000-08-14 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mobile Source Emissions Factor (MOBILE) model is a computer model developed by the U.S. Environmental Protection Agency (EPA) for estimating emissions from on-road motor vehicles. MOBILE is used in air-quality planning and regulation for estimating emissions of carbon monoxide (CO), volatile organic compounds (VOCs), and nitrogen oxides (NOx) and for predicting the effects of emissions-reduction programs. Because of its important role in air-quality management, the accuracy of MOBILE is critical. Possible consequences of inaccurately characterizing motor-vehicle emissions include the implementation of insufficient controls that endanger the environment and public health or the implementation of ineffective policies that impose excessive control costs. Billions of dollars per year in transportation funding are linked to air-quality attainment plans, which rely on estimates of mobile-source emissions. Transportation infrastructure decisions are also affected by emissions estimates from MOBILE. In response to a request from Congress, the National Research Council established the Committee to Review EPA's Mobile Source Emissions Factor (MOBILE) Model in October 1998. The committee was charged to evaluate MOBILE and to develop recommendations for improving the model.

Download or read book Validation of Traffic Simulation Model Output for Work Zone and Mobile Source Emissions Modeling and Integration with Human in the loop Driving Simulators written by Shauna L. Hallmark and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The next generation motor vehicle emission rate model used in the US, the United States Environmental Protection Agency's Motor Vehicle Emmission Simulator (MOVES), requires second-by-second vehicle data in order to fully utilize model capabilities. However, field data collection of this type of data is resource intensive and frequently not realistic for local agencies. Some microsimulation models have the capability of outputting instantaneous speed and acceleration, which can be used in MOVES. With these capabilities, microsimulation offers a valuable tool to conduct analysis requiring a large number of data. ... Two case studies were used to assess the utility of the microsimulation model, Vissim, in developing output that can be used as input to MOVES. In one scenario, drivers were selected to drive an instrumented test vehicle along a test corridor. In another scenario, five drivers drove through a roundabout in the University of Iowa national Advanced Driving Simulator (NADS). Models for each scenario were also developed in Vissim. Model output was compared to field collected speed/acceleration profile data to assess the accuracy of microsimulation models in providing realistic estimates of vehicle activity as input to MOVES. Results were summarized to demonstrate the applicability of linking microsimulated vehicle activity data with emissions models to better estimate the emission impacts of different transportation strategies" (page vii).

Download or read book The Development of a Transportation emissions Model Using a Distributed Client Server Architecture written by Cheng Zhao and published by . This book was released on 1995 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Traffic Flow Dynamics written by Martin Treiber and published by Springer Science & Business Media. This book was released on 2012-10-11 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a comprehensive and instructive coverage of vehicular traffic flow dynamics and modeling. It makes this fascinating interdisciplinary topic, which to date was only documented in parts by specialized monographs, accessible to a broad readership. Numerous figures and problems with solutions help the reader to quickly understand and practice the presented concepts. This book is targeted at students of physics and traffic engineering and, more generally, also at students and professionals in computer science, mathematics, and interdisciplinary topics. It also offers material for project work in programming and simulation at college and university level. The main part, after presenting different categories of traffic data, is devoted to a mathematical description of the dynamics of traffic flow, covering macroscopic models which describe traffic in terms of density, as well as microscopic many-particle models in which each particle corresponds to a vehicle and its driver. Focus chapters on traffic instabilities and model calibration/validation present these topics in a novel and systematic way. Finally, the theoretical framework is shown at work in selected applications such as traffic-state and travel-time estimation, intelligent transportation systems, traffic operations management, and a detailed physics-based model for fuel consumption and emissions.

Download or read book Integration of Modal Vehicle Emission Models with the TRANSIMS Traffic Simulation Module written by and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRANSIMS is a set of integrated analytical and simulation models and supporting data bases. The TRANSIMS methods deal with individual behavioral units and proceed through several steps to estimate travel. TRANSIMS predicts trips for individual households, residents and vehicles rather than for zonal aggregations of households. TRANSIMS also predicts the movement of individual freight loads. A regional microsimulation executes the generated trips on the transportation network, modeling the individual vehicle interactions and predicting the transportation system performance. The purpose of the TRANSIMS environmental module is to translate traveler behavior into consequent air quality, energy consumption, and carbon dioxide emissions. There are four major tasks required to translate traveler behavior into environmental consequences: (1) estimate the emissions, (2) describe the atmospheric conditions into which the contaminants are emitted, (3) describe the local transport and dispersion, and (4) describe the chemical reactions that occur during transport and dispersion of the contaminants.

Download or read book Improving Transportation Emissions Modeling by Integrating Ground Counts with Travel Demand Model Forecasts written by Kuo-Shian Lin and published by . This book was released on 1997 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Impact of Dynamic Assignment Methods and Speed Variability on Regional Vehicle Emissions Inventories written by Song Bai and published by . This book was released on 2006 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Review of Instantaneous Emission Models for Road Vehicles written by P. G. Boulter and published by . This book was released on 2007 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Transportation Emissions Using Radar Based Vehicle Detection Data written by Lang Yu and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation introduces a new and novel methodology for estimating vehicle emissions at signalized intersections. Radar based vehicle detection systems, when placed at intersection approaches, is able to track vehicle operational characteristics at very high frequency, thus provides an ideal data source for emission estimation. By combining radar based vehicle detection data and MOVES project level analysis operating mode distribution approach, a real-time emission estimation system for signalized intersections is proposed. The Emission Computation Tool for Radar Data is developed to facilitate the automatic and continuous computation of operating mode distribution and emissions. The emission rates computed can also be integrated with existing air dispersion models in order to be used for air quality conformity and hot spot analysis. A case study is conducted to test the feasibility and validity of the proposed real-time emission estimation system. The results showed that the data collected should be used for computing a variety of parameters, including traffic volume, average speed, operating mode distribution, total emissions and emission rates for various pollutants. With emission rates, existing pollutant dispersion models such as AERMOD are applied, yielding pollutant concentrations at various locations, providing additional functionalities to the system. Evaluation results showed that the traffic volume and emission rates computed matches closely with AADT data and EPA's emission standards. Finally, an operating mode based macroscopic emission model is developed by using both empirical data from the case study as well as incorporating existing traffic flow dynamics model. This predictive model is based on estimating total time spent in each operating mode directly from traffic demand and other variables. Total time idling is modeled using kinematic wave theory and queuing theory, while others are modeled using empirical data. The validation results showed that the model is able to achieve a high degree of accuracy, within approximately 10 percent of emission results computed using the radar data. In conclusion, both the proposed real-time emission estimation system at signalized intersections and the emission model developed showed to yield highly accurate and detailed results, and are applicable in real world intersection locations.

Download or read book Collection and Evaluation of Modal Traffic Data for Determination of Vehicle Emission Rates Under Certain Driving Conditions written by Lei Yu and published by . This book was released on 1997 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessing the Emissions and Fuel Consumption Impacts of Intelligent Transportation Systems written by and published by . This book was released on 1998 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Models for Vehicular Traffic on Networks written by Mauro Garavello and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Real time Vehicle Emission Estimation Using Traffic Data written by Anjie Liu and published by . This book was released on 2019 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current state of climate change should be addressed by all sectors that contribute to it. One of the major contributors is the transportation sector, which generates a quarter of greenhouse gas emissions in North America. Most of these transportation related emissions are from road vehicles; as result, how to manage and control traffic or vehicular emissions is therefore becoming a major concern for the governments, the public and the transportation authorities. One of the key requirements to emission management and control is the ability to quantify the magnitude of emissions by traffic of an existing or future network under specific road plans, designs and traffic management schemes. Unfortunately, vehicular traffic emissions are difficult to quantify or predict, which has led a significant number of efforts over the past decades to address this challenge. Three general methods have been proposed in literature. The first method is for determining the traffic emissions of an existing road network with the idea of measuring the tail-pipe emissions of individual vehicles directly. This approach, while most accurate, is costly and difficult to scale as it would require all vehicles being equipped with tail-pipe emission sensors. The second approach is applying ambient pollutant sensors to measure the emissions generated by the traffic near the sensors. This method is only approximate as the vehicle-generated emissions can easily be confounded by other nearby emitters and weather and environmental conditions. Note that both of these methods are measurement-based and can only be used to evaluate the existing conditions (e.g., after a traffic project is implemented), which means that it cannot be used for evaluating alternative transportation projects at the planning stage. The last method is model-based with the idea of developing models that can be used to estimate traffic emissions. The emission models in this method link the amount of emissions being generated by a group of vehicles to their operations details as well as other influencing factors such as weather, fuel and road geometry. This last method is the most scalable, both spatially and temporally, and also most flexible as it can meet the needs of both monitoring (using field data) and prediction. Typically, traffic emissions are modelled on a macroscopic scale based on the distance travelled by vehicles and their average speeds. However, for traffic management applications, a model of higher granularity would be preferred so that impacts of different traffic control schemes can be captured. Furthermore, recent advances in vehicle detection technology has significantly increased the spatiotemporal resolutions of traffic data. For example, video-based vehicle detection can provide more details about vehicle movements and vehicle types than previous methods like inductive loop detection. Using such detection data, the vehicle movements, referred to as trajectories, can be determined on a second-by-second basis. These vehicle trajectories can then be used to estimate the emissions produced by the vehicles. In this research, we have proposed a new approach that can be used to estimate traffic generated emissions in real time using high resolution traffic data. The essential component of the proposed emission estimation method is the process to reconstruct vehicle trajectories based on available data and some assumptions on the expected vehicle motions including cruising, acceleration and deceleration, and car-following. The reconstructed trajectories containing instantaneous speed and acceleration data are then used to estimate emissions using the MOVES emission simulator. Furthermore, a simplified rate-based module was developed to replace the MOVES software for direct emission calculation, leading to significant improvement in the computational efficiency of the proposed method. The proposed method was tested in a simulated environment using the well-known traffic simulator - Vissim. In the Vissim model, the traffic activities, signal timing, and vehicle detection were simulated and both the original vehicle trajectories and detection data recorded. To evaluate the proposed method, two sets of emission estimates are compared: the "ground truth" set of estimates comes from the originally simulated vehicle trajectories, and the set from trajectories reconstructed using the detection data. Results show that the performance of the proposed method depends on many factors, such as traffic volumes, the placement of detectors, and which greenhouse gas is being estimated. Sensitivity analyses were performed to see whether the proposed method is sufficiently sensitive to the impacts of traffic control schemes. The results from the sensitivity analyses indicate that the proposed method can capture impacts of signal timing changes and signal coordination but is insufficiently sensitive to speed limit changes. Further research is recommended to validate the proposed method using field studies. Another recommendation, which falls outside of this area of research, would be to investigate the feasibility of equipping vehicles with devices that can record their instantaneous fuel consumption and location data. With this information, traffic controllers would be better informed for emission estimation than they would be with only detection data.

Download or read book Traffic Simulation and Data written by Winnie Daamen and published by CRC Press. This book was released on 2014-09-17 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: A single source of information for researchers and professionals, Traffic Simulation and Data: Validation Methods and Applications offers a complete overview of traffic data collection, state estimation, calibration and validation for traffic modelling and simulation. It derives from the Multitude Project-a European Cost Action project that incorpo

Download or read book Modeling Mobility with Open Data written by Michael Behrisch and published by Springer. This book was released on 2015-03-11 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This contributed volume contains the conference proceedings of the Simulation of Urban Mobility (SUMO) conference 2014, Berlin. The included research papers cover a wide range of topics in traffic planning and simulation, including open data, vehicular communication, e-mobility, urban mobility, multimodal traffic as well as usage approaches. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.