All vehicles are described by attributes that are common to all of the study vehicles, e.g., range. The attribute levels are varied over several trials to elicit different choices. With these data, econometric models are run to estimate the partial utility values for consumer preferences of each attribute Turrentine and Kurani argue that the underlying assumptions of consumer behavior in many EV Stated preference studies are flawed. These studies assume that the survey respondents have well-formed preferences for driving range, for example. Second, they assume that these preferences remain stable to forecast changes in preferences . Finally, these studies evaluate several vehicle attributes, which study participants have not yet experienced. Consequently, it is very difficult to explore the market for unknown technologies. Demonstration projects can provide a useful platform for examining early reactions and traveler responses to new transportation technologies. In the absence of such field studies, many researchers rely upon Delphi techniques–repeated queries of a panel of respondents–to explore the potential market for ITS technologies. In this evaluation, researchers conducted a modified Delphi evaluation of the market for various ITS technologies to construct the ITS scenarios, which include market penetration estimates, that will be used in the modeling exercise in this study. The modeling results will be used to identify and prioritize a range of ITS technologies on the basis of a set of energy and environmental criteria.Results from ITS operational tests underscore the importance of user acceptance in estimating the environmental impacts of ITS. For example, the SmarTraveler project in Boston found that nearly half of those who used the services changed their travel behavior in ways that could reduce traffic congestion. Nevertheless, system usage remained “too low by any measure to provide noticeable impacts on congestion” . As cited above, Van Aerde and Rakha showed for Orlando’s TravTek that emission impacts were a function of market penetration, 25 liter pot and could even switch from negative to positive depending on market penetration. This section presents an overview of various market penetration estimates that have been made for the ITS technologies examined in this study.
The market penetration results presented here serve as context and comparative points for the estimates we produced in our modified Delphi study. As with the emission studies reviewed earlier, each of these market studies was conducted using differing methods and a variety of ITS descriptions. As mentioned above, One common methodological approach has been the use of Delphi techniques. This technique is designed to facilitate the convergence of the estimates provided by experts.In 1992 the Volpe National Transportation Systems Center was commissioned by the Federal Highway Administration ITS Joint Program Office to develop an analytical framework to predict ITS impacts and assess the potential benefits of ATMS user services. The study focused on ATMS under the premise that it provides the foundation for other types of ITS services. Within the bundle of ATMS services, the study concentrated on ramp metering, signal coordination, integrated traffic management systems, and HOV lanes and ramp meter HOV bypass lanes. The framework integrates a regional planning model with freeway and arterial simulation models, which provide input to emission models, a fuel consumption model, and a safety model. The emission modeling component of the framework uses MOBILE5a and EMFAC7F to provide emission rates for input to EMISSION and EMIS . The EMIS model also provides the structure for applying fuel consumption rates to link-based data. The fuel consumption rate model used for this study was developed by the Caltrans Office of the Transportation Laboratory in cooperation with the US DOT and the FHWA . A new safety model was developed specifically for the framework, incorporating safety factors that were determined from historical accident data for the study corridor. The US DOT framework generates a set of MOEs that can be used to evaluate the impact of implementing ATMS user services. The MOEs are categorized under four major impact areas: congestion or operational measures; emissions; fuel consumption; and safety. No attempt was made to distinguish between supply- and demand-related impacts as in Brand . The framework was applied to model five alternative ATMS scenarios and the results were compared to those for a baseline configuration. The scenarios were made up of various combinations of fixed time and demand-based signal coordination with fixed time and synchronized freeway ramp metering.
A summary of the findings of these analyses are presented in the section of this report titled “Quantitative Assessment: Modeling Studies.”Brand describes an evaluation framework that is designed to be sensitive to the differences between ITS and traditional transportation improvements. An extensive set of evaluation criteria is presented, distinguishing between the supply and demand impacts of ITS deployment. The criteria are categorized into five main impact types. The first two criteria types, increased operational efficiency and increased output , are separated to avoid the possibility of dramatically underestimating the benefits of a given technology. These criteria are also structured in a second dimension explicitly to address the time frame of the impacts . The additional criteria types are safety, energy and environmental, and implementation impacts. Brand shows how the full set of criteria can be grouped to avoid double-counting of benefits because of the correlations that exist between certain criteria. An example also demonstrates how evaluation criteria can be weighted to allow the evaluator to produce an overall weighted measure of merit for each project. Finally, Brand provides default values to evaluate ITS improvements for inclusion in transportation system plans.Lo et al. developed a framework for comparison of dynamic traffic models, emphasizing the dimensions of functionality, traffic and route choice dynamics, and overall network performance. The framework is set up to compare the models against a check-list of functions and also to compare the ability of each tool to model twelve scenarios developed for five different test networks. The report provides a list of performance measures to be determined for each modeling tool and a discussion of how the results are to be interpreted. The comparison framework is designed to be generic and permit comparison of many traffic models. However, four specific models were selected for comparison in this study: INTEGRATION, DYNASMART, DINOSAUR, and METS. The comparison results and the impact of perturbations to O-D data will be presented in Part II and III of the report, which are almost complete. Some of the traffic simulation tools mentioned above are capable of estimating the energy and environmental impacts of the simulated traffic conditions . Others can provide output suitable for input to some fuel consumption and emission models. However, raspberry cultivation pot modeling frameworks that provide output suitable for average speed based emission models such as the US EPA MOBILE and the California Air Resources Board EMFAC models are not capable of providing accurate assessments of the environmental impacts of the ITS scenarios being considered.
The MOBILE and EMFAC emission factors predict vehicle emissions based in part on average trip speeds and a large number of FTP bag emission measurements. These models are intended to predict regional emission inventories, and hence they are not adequate for evaluating microscopic-level operational improvements, such as those achieved by ITS strategies. To evaluate the emission benefits of such systems, it is necessary to employ an emission model that considers the modal operation of a vehicle . The INTEGRATION and DYNASMART models make use of modal emission models that account for microscopic changes in vehicle speed profiles and Ramachandran , respectively. A brief summary of these models is presented in the sections below .Much has been written about the capabilities of the INTEGRATION traffic simulation model . This section presents some of the aspects of this model that are relevant to our research. For more detailed information about the model development, capabilities, limitations, and applications, the reader is referred to the reports just mentioned and the INTEGRATION User’s Guide . The INTEGRATION traffic simulation model was developed by Michel Van Aerde of Queen’s University in Ontario, Canada . This microscopic simulation model was developed with the purpose of simulating integrated networks composed of freeways and arterial roads, with a particular emphasis on modeling ITS scenarios. INTEGRATION 2.0 simulates the behavior of individual vehicles on signalized arterial and mainline freeway links, with the ability to model merges, diverges, and weaving sections. The model contains algorithms to simulate many aspects of traffic behavior including: lane changing; link-to-link lane transitions; car following; route selection and traffic assignment; signal cycles,including turning movements, shock waves, over saturation delay, and gap acceptance at traffic signals; signal coordination; stop and yield signs; and incidents and diversions. INTEGRATION also provides estimates of effectiveness measures for individual vehicles; links; O-D pairs; and complete networks, including link travel time, fuel consumption, and vehicle emissions.The revised ozone standard is intended to replace the current one-hour standard with an eight-hour standard. However, the one-hour standard will continue to apply to areas not attaining it for an interim period to ensure an effective transition to the new eight-hour standard. Title I of the CAA addresses the requirements for different classifications of non attainment areas that do not meet the current one-hour standard . These requirements include such items as: 1) mandatory control measures, 2) annual rate of progress requirements for emission reductions, and 3) offset ratios for the emissions from new or modified stationary sources. These requirements have contributed significantly to the improvements in air quality since 1990. Based on the US EPA’s legal review, the Agency has concluded that Title I should continue to apply as a matter of law for the purpose of achieving attainment of the current one-hour standard. Once an area attains the one-hour standard, those provisions will no longer apply and the area’s implementation of the new eight-hour standard would be governed only by the provisions of Title I. To streamline the process and minimize the burden on existing non attainment areas, the one-hour standard will cease to apply to an area upon a determination by the US EPA that an area has attained air quality that meets the one-hour standard.
In light of the implementation of the new eight-hour standard, which is more stringent than the existing one-hour standard, States will not have to prepare maintenance plans for those areas that attain the one-hour standard. For areas where the air quality does not currently attain the one-hour standard, the one-hour standard will continue in effect. The provisions of Title I would also apply to designated non attainment areas until the time each area has met the one-hour air quality standard. At that time, the US EPA will take action so that the one-hour standard no longer applies to such areas. In any event, the “bump-up” provisions of Subpart 2, of Part D of Title I, which require that areas not attaining the standard by the applicable attainment date be reclassified to the next higher classification, will not be triggered by the failure of any area to meet the new eight-hour standard. The purpose of retaining the current standard is to ensure a smooth legal and practical transition to the new standard .For areas that attain the one-hour standard but not the new eight-hour standard, the US EPA will follow a flexible implementation approach that encourages cleaner air sooner, responds to the fact that ozone is a regional as well as local problem, and eliminates unnecessary planning and regulatory burdens for State and local governments. A primary element of the plan will be the establishment under Section 172 of the CAA of a special “transitional” classification for areas that participate in a regional strategy and/or that opt to submit early plans addressing the new eight-hour standard. Because many areas will need little or no additional new local emission reductions to reach attainment, beyond those reductions that will be achieved through the regional control strategy, and will come into attainment earlier than otherwise required, the US EPA will exercise its discretion under the law to eliminate unnecessary local planning requirements for such areas. The US EPA will revise its rules for new source review and conformity so that States will be able to comply with only minor revisions to their existing programs in areas classified as transitional.