Shomik Raj Mehndiratta

Analyzing Cell Phone Location Data for Urban Travel: Current Methods, Limitations, and Opportunities

Travelers today use technology that generates vast amounts of data at low cost. These data could supplement most outputs of regional travel demand models. New analysis tools could change how data and modeling are used in the assessment of travel demand. Recent work has shown how processed origin–destination trips, as developed by trip data providers, support travel analysis. Much less has been reported on how raw data from telecommunication providers can be processed to support such an analysis or to what extent the raw data can be treated to extract travel behavior. This paper discusses how cell phone data can be processed to inform a four-step transportation model, with a focus on the limitations and opportunities of such data. The illustrated data treatment approach uses only phone data and population density to generate trip matrices in two metropolitan areas: Boston, Massachusetts, and Rio de Janeiro, Brazil. How to label zones as home- and work-based according to frequency and time of day is detailed. By using the labels (home, work, or other) of consecutive stays, one can assign purposes to trips such as home-based work. The resulting trip pairs are expanded for the total population from census data. Comparable results with existing information reported in local surveys in Boston and existing origin–destination matrices in Rio de Janeiro are shown. The results detail a method for use of passively generated cellular data as a low-cost option for transportation planning.

Analysis of Discrete Choice Data with Repeated Observations: Comparison of Three Techniques in Intercity Travel Case

With the acceptance and widespread application of stated preference methods in transportation analysis, there has been a need for the analysis of choice data with repeated observations. Analysis of repeated choice data is complicated by correlation of responses across the choices made by a single individual. In the probit framework, repeated choice can easily be accommodated by way of correlation in the utilities associated with the errors. However, the probit framework has computational limitations; subsequently, researchers have looked to modeling repeated choice by using extensions of the logit model. Random parameter logit models estimated by simulation methods provide a promising modeling framework. The estimation results of some stated preference intercity business travel data are compared by using three alternative estimation techniques to account for correlations across the choices made by a single individual. It is believed that two of the alternative methods, which use random-parameter logit models (developed by researchers for use in an energy application), have not been used before in the transportation context. A comparison of the three techniques provides documentation for researchers and practitioners who plan to analyze such data.

Application of Benefit-Cost Analysis to the Proposed California High-Speed Rail System

A high-speed rail system operating on a dedicated right-of-way that results in a significant volume of trips being diverted from the air and highway modes can be expected to generate significant benefits. The major benefits that will accrue to both users and nonusers from the construction and operation of such a system are described. Both intercity and urban travel benefits are included in the analysis. A methodology for how these diverse benefits can be quantified is presented, and, importantly, it is shown how these benefits can be monetized for input into a comprehensive benefit-cost analysis. Of the 11 types of benefits examined, 4 were found to produce the bulk of the benefits of the high-speed rail system. For the present purposes, benefit-cost analysis is a public-sector evaluation tool that compares all the benefits of a project to society with all the costs of a project. The objective is to ascertain whether all the benefits do in fact exceed all the costs. The major benefits include the revenues derived from high-speed rail users, the high-speed rail user benefits (consumer surplus) net of fares paid, the travel time savings to urban commuters, and the value of time savings to intercity air travelers. Actual data have been taken from the proposed California highspeed rail system to illustrate the benefits that can be expected from such a system and the discrete steps that have been undertaken in the benefit-cost analysis.

Impact of slot controls with a market-based allocation mechanism at San Francisco International Airport

This paper presents an empirical analysis of the possible impact of the application of slot controls as a demand-management measure at San Francisco International Airport (SFO). We examine the specific case of slot controls allocated with a market-based mechanism. The paper first describes the nature of the delay problem at SFO and how slot controls would work to manage demand, briefly reviewing their history in the US. We then describe the methodology used to analyze their potential impact given the assumption of a market-based allocation mechanism and present our findings on their predicted impacts on arrival delays and the nature and level of scheduled passenger air service at the airport. Finally, we present conclusions as to the overall potential of slot controls to alleviate delay at SFO and their non-delay consequences. The methods presented in the paper facilitate a detailed analysis of the incidence of the impact of slot controls on passengers, airlines and individual communities that depend on SFO for access to the national air transportation system.

Likely Users of Advanced Traveler Information Systems: Evidence from the Seattle Region

Findings about the claimed use of and interest in traveler information systems among segments of the general population in the Seattle metropolitan region are reported. The research is based on data collected from a 1997 intelligent transportation system supplement to the Puget Sound Regional Council’s transportation panel travel diary study. In general, interest in traffic information was found to be a function of complex travel behavior, demographics, and factors related to attitudinal and technology interest. It was also found that the potential market for advanced traveler information systems (ATIS) includes several market segments with different needs; each is drawn to ATIS for distinct and varying reasons. First, the so-called control seeker segment includes people who desire greater than average control over their environment. In a traffic information context, that translates to better knowledge of their travel times, especially in congested travel environments. The second segment of interest, dubbed webheads, includes individuals who are very comfortable with high technology, and it is possible that they would be drawn to ATIS at least partially through specific high-technology dissemination media. A third segment is made up of individuals who are less comfortable with (or less interested in) technology and are primarily interested in pretrip information, which they use to make departure time and route choice decisions.

HOW TRANSPORTATION PLANNERS AND DECISION MAKERS ADDRESS RISK AND UNCERTAINTY

A wide cross section of transportation planners was interviewed to understand how issues related to risk and uncertainty are presently addressed in the metropolitan transportation planning process. The results and insights from these interviews are reported. It was found that many of the current responses to risks in making decisions on transportation investments could usefully be explained and improved upon by the new options approach. The examples and the analyses of the interviews show that metropolitan planning organization planners and more senior transportation executives and decision makers are certainly aware of the risks they face in investing in major transportation projects. Furthermore, they already are capable of responding to those risks in ways that can be better appreciated and explained by the options approach. What is missing in metropolitan transportation planning, and in the public-sector investment community at large, is an appreciation that there are advantages to identifying and analyzing risks early in the planning process, and that investments involving risk can be systematically analyzed in a risk management plan that uses the real-options approach. This may result in (much) higher value investments to accomplish the stated investment goals, while avoiding serious mistakes in investing in projects that may fall far short of the investment goals.

Urban Rail Development in China: The Challenges Ahead

This paper provides an overview of the recent development of urban rail systems in Chinese cites and the challenges ahead. China is set to become the world leader in length of metro lines in operation in the near to medium term. In view of the large scale of this investment, a focus on the overall economic and financial viability of these systems is needed. On the basis of analytical work supporting a project investment in the city of Kunming and a study tour of urban rail systems in China, this paper highlights four areas believed to be crucial in meeting these objectives: integration of new metro systems with existing systems of public transport, a supportive overall urban transport policy, transit-oriented development, and long-term financial sustainability. The conclusion is that in all of these areas, China possesses tools that may enable the program to succeed if they are used effectively and in concert. Any issues appear to result from a lack of attention to these four areas and from a managerial focus on ensuring the completion of the construction program above all other concerns. The RMB 1 trillion investment in urban rail construction under way in China needs to be a catalyst for joint action on the issues identified in this paper (RMB 1 is approximately US

Options Approach to Risk Analysis in Transportation Planning

0.15). Otherwise, Chinese cities may be left with an investment that carries large long-term costs and does not deliver the crucial economic benefits expected.

Short-term delay mitigation strategies for San Francisco International Airport

The applicability of the real-options approach to risk management to the metropolitan transportation planning process is described. The options approach to risk analysis brings to investment decisions the insight that there is an inherent value in option-creating actions (by resolving uncertainty, enabling flexibility, or uncovering new and relevant information) and a cost associated with exercising options (irreversible commitments of resources and time). The options approach moves investment decision making from simply choosing whether to build a project to a regime that considers a range of possible decisions, with the potential value of each decision measured in terms of its option-creation value and irreversible commitment cost. This approach is specifically designed to maximize the value of investments having the characteristics of transportation projects that are subject to uncertainty and risk in their outcomes. Also described is the new options approach; examples that illustrate the value of different kinds of options are given. By recognizing the value of improved information—and actions to obtain it—the options approach can give real impetus to improved planning methods. Because the analysis tools provided by the options approach make it possible to value the additional information that improved planning can provide, recommendations are provided on how—and in what parts of the metropolitan transportation planning process—the new tools of risk analysis can most appropriately be applied.

WHAT ADVANCED TRAVELER INFORMATION SYSTEM INFORMATION DO USERS WANT? EVIDENCE FROM IN-VEHICLE NAVIGATION DEVICE USERS

San Francisco International Airport (SFO) is typical of many large airports in that rapid growth in air travel has outpaced its available runway capacity, leading to serious delays. At the same time, SFO represents a unique circumstance because of the role of its local climate, and thus careful analysis is required to address its delay situation. The airport is in the process of planning a major runway reconfiguration project that would largely solve the problem of weather-related congestion delays, but this massive project will take many years. Presented are the results of an effort to design potential short-term strategies to reduce weatherrelated congestion delay at SFO while the runway reconfiguration proceeds. Designing measures to reduce delay outside the context of runway expansion is a complex task that requires balancing multiple considerations—issues of equity, access, legal jurisdiction—along with considerations of efficiency and airport performance. The kinds of thinking and analysis required in considering these types of delay-reduction measures are explored.