The growing number of trucks traveling on freeways has caused more traffic congestion and increased the likelihood of truck-related crashes. Many transportation agencies are considering a new concept of truck-only toll (TOT) lanes to provide a more efficient and safer freight transportation system. This research develops a methodology for identifying candidate TOT lanes in the freeway system. The modeling of TOT lanes in different geographic applications includes individual TOT corridors, a regional TOT network, and a statewide TOT network. The criteria employed in a geographic information system (GIS)-based screening process to determine feasible TOT corridors and their boundaries/extents include: freeway level of service, truck volumes, truck percentage of total freeway flow, truck-related crashes, and truckers willingness to pay. The research also presents the process for determining optimum toll rates for TOT lanes. Furthermore, this research addresses issues of assessing the engineering design of TOT lane placement and the performance measures of using either mandatory or voluntary TOT lanes. This research also examines freeway performance under two scenarios -- adding general purpose lanes or building TOT lanes with both mandatory and voluntary use. Finally, this research addresses the strategies for critical issues associated with the planning, design, and operation of TOT lanes and presents TOT planning guidance.

Value pricing strategies are beginning to be considered for future improvements in suburban areas that currently do not experience significant congestion but are expected to become congested in the future. This is a significant departure from implementing these strategies in congested urban areas as is commonly done now. Therefore, traveler reaction in these suburban areas is unknown. To plan and design value pricing projects most effectively, it will be necessary to gain an understanding of suburban travelers' potential reaction to value pricing. Responses to a survey of travelers using the eastern and western segments of Interstate 10 (I-10) outside of San Antonio were used to study differences in response to value pricing by suburban population groups. These surveys collected information on travelers' socioeconomic and trip characteristics as well as their attitudes towards value pricing in the form of potential Express Toll Lanes (ETLS). Stated preference scenarios presented to survey respondents were used to develop mode choice models. These models were used to determine characteristics that may impact the decision to choose to travel on the general purpose lanes (GPLs) or the ETLs. This research suggests that the implementation of value pricing strategies on suburban corridors may pose a challenge from a policy standpoint. The populations using these corridors appear to be more varied in their responses toward value pricing than populations using congested urban corridors. Overall, it was found that the majority of travelers on I-10E and I-10W are not favorable to the implementation of value pricing for the future expansion of these corridors. However, I-10W travelers seem to be more willing to pay for travel time savings. This is likely due to the fact that travelers on I-10W earn higher average incomes, are more likely to use I-10W on a regular basis for commute purposes, and are more often exposed to some traffic congestion. Conversely, travelers on I-10E are more likely to use I-10E less frequently for non-commute trips, travel longer distances, and probably do not have an intuitive sense of the value they would place on travel time savings since they do not regularly experience congestion.

The High Occupancy Vehicle (HOV) lanes on Atlanta, Georgia’s radial I-85 had long been providing sub-optimal throughput in the peak traffic hours, as the two-person occupancy requirement allowed the lanes to become heavily congested. The Georgia Department of Transportation converted 15.5 miles of HOV 2+ lanes to High Occupancy Toll (HOT) lanes, one in each direction on I-85. The lanes use dynamic value pricing to set toll levels based on the volume and average speed of traffic in the lanes. The goal of this research was to investigate the responses to toll lane pricing and the factors that appear to inform lane choice decisions, as well as examining values of travel time savings and toll price elasticity for users of the Express Lanes. This study of the metropolitan Atlanta I-85 Express Lanes operates at the microscopic level to examine the impact of demographic characteristics, congestion levels, and pricing on users’ decisions to use or not use the I-85 Express Lanes. The dissertation examined the value of travel time savings distributions across income segments. The differences in these distributions among lower, medium, and higher income households were marginal at best. The results did not indicate that higher income households had the highest value of travel time savings results, as may have been expected. The modeling work performed here provided a number of insights into toll lane use. The determinants of lane choice decision-making in the morning peak had notable differences from the determinants of the afternoon peak. The initial analysis involved models which were estimated across three different income segments to examine differences in decision making between low, medium, and higher income households. The results indicated that the parameters were largely consistent across the three segments. Further segmenting the households showed that lane choice determinants varied more within the ‘Higher’ income segment than across the original three-segment structure. In particular, the five-segment models illustrated lower elasticities with regard to corridor segment counts and toll levels for the highest-income households in the sample, as well as higher household income level elasticities for afternoon trips by that same cohort. The research was among the first in the available literature to use revealed preference lane use data for both the toll lane users and the unpriced general purpose lane users. The use of household level marketing data, rather than census or survey data, was another unique characteristic of this research. The analysis of value of travel time savings with a demographic component that looks at household income has not yet been seen in the literature; similarly, the findings regarding differing behavior among very high income households appear to be unseen in the existing literature. The results from this analysis, such as willingness-to-pay values for different population segments, will be useful inputs to the decisions surrounding future HOT implementations in the Atlanta region. The use of new data sources, the evaluation of those types of data sources, and the application of methods that have previously been unused in this field make up the primary contributions of this dissertation.

Thesis (M.S. in Civil and Environmental Engineering)--University of California, Davis, 2007. / Text document in PDF format. Title from PDF title page (viewed on August 28, 2009). "Received by ITS-Davis: November 2007"--Publication detail webpage. Includes bibliographical references (p. 110-115).

abstract: Managed Lanes (MLs) have been increasingly advocated as a way to reduce congestion. This study provides an innovative new tolling strategy for MLs called the travel time refund (TTR). The TTR is an “insurance” that ensures the ML user will arrive to their destination within a specified travel time savings, at an additional fee to the toll. If the user fails to arrive to their destination, the user is refunded the toll amount. To gauge interest in the TTR, a stated preference survey was developed and distributed throughout the Phoenix-metropolitan area. Over 2,200 responses were gathered with about 805 being completed. Exploratory data analysis of the data included a descriptive analysis regarding individual and household demographic variables, HOV usage and satisfaction levels, HOT usage and interests, and TTR interests. Cross-tabulation analysis is further conducted to examine trends and correlations between variables, if any. Because most survey takers were in Arizona, the majority (53%) of respondents were unfamiliar with HOT lanes and their practices. This may have had an impact on the interest in the TTR, although it was not apparent when looking at the cross-tabulation between HOT knowledge and TTR interest. The concept of the HOT lane and “paying to travel” itself may have turned people away from the TTR option. Therefore, similar surveys implementing new HOT pricing strategies should be deployed where current HOT practices are already in existence. Moreover, introducing the TTR concept to current HOT users may also receive valuable feedback in its future deployment. Further analysis will include the weighting of data to account for sample bias, an exploration of the stated preference scenarios to determine what factors were significant in peoples’ choices, and a predictive model of those choices based on demographic information. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2015

In the US transportation system, environmental justice (EJ) issues are regulated by a variety of laws to ensure that all have fair treatment with respect to implementation of policies. If State Departments of Transportation adhere to all regulations properly but unconsciously, then an underlying negative impact on a community may still exist as a result of a newly implemented project. Since the implementation of High Occupancy Toll (HOT) lanes are fairly new, and since there have been numerous concerns from the public about their discriminatory nature, a decision support system is needed to identify potential EJ violations and issues when implementing a new or converted HOT lane. No prior model exists. The goal of this research is to assist state's Department of Transportation (DOT) in the early stages of the development of an HOT lane by developing a Potential Environmental Justice Violation Model that will help state agencies predict potential EJ violations before additional resources are invested into a project. By developing a model, this study identifies and classifies characteristic drivers of potential EJ violations related to communities' economic, social, or health and safety status. The Potential Environmental Justice Violation Model (PEJVM) allows state DOTs employees to define and evaluate the distribution of impacts in the relevant categories. The model provides a method for transforming complex qualitative and quantitative data about a project into a user-friendly format where the results can then be visualized using a spider radar diagram to determine the level of impact of each identified variable. The PEJVM was validated using two previous anonymous HOT case studies and demonstrated using the Interstate 85 Case Study in Atlanta, Georgia. This model offers a uniform method of identifying potential environmental justice violations when implementing a HOT lane. The model will also help inform state agencies of potential violations early in the planning stages of HOT lane projects so that the agency can solve any potential EJ issues before additional resources are invested.