working paper

Twenty Seconds that Shook the Agenda: An Assessment of Transportation Issues in the Mass Media Following the Northridge Earthquake

Publication Date

June 30, 1995

Author(s)

Abstract

This study investigates how transportation issues were conveyed by the mass media, following the January 17, 1994 Northridge earthquake in Los Angeles. It is shown that the media are a vital tool for transportation planners, when a disaster causes damage to major arterials. The media are the primary means through which the public assesses damage to the transportation system, and learns which roadways and detours to use. They are also studied by out-of-town officials, who must appraise the damage. The media also expose people to new travel alternatives, like bus, carpooling, and rail service. 

A content-analysis is used to study trends in major mass media, including radio, local and national television, and newspapers. This technique was used to quantify the volume of transportation news, as well as changes in emphasis over time. A number of related issues were investigated through content analysis including change in the overall level of traffic news; change in information about alternative modes, like train service and buses; and change in news about freeway recovery and rebuilding efforts. It is observed that stories about transportation were a regular, and continuous component of earthquake reports.

Phd Dissertation

Modular neural network architecture for detection of operational problems on urban arterials

Abstract

A major concern in Advanced Transportation Management Systems (ATMS), one of the principal thrusts of the national program on Intelligent Transportation Systems (ITS), is providing decision support to effectively detect, verify and develop response strategies for incidents that disrupt the flow of traffic. A key element of providing such support is automating the process of detecting operational problems on large area networks. Successful detection of operational problems in their early stages is vital for formulating response strategies such as modifying surface street signal timing plans and activating or updating traveler information systems, including changeable message signs, in-vehicle navigation systems and highway advisory radio, altering emergency services, amongst others. Reliable surface street incident detection is also necessary for the development of integrated freeway-arterial control systems. Incident detection has been the subject of research for the past two decades. But the focus has been on detecting capacity reducing non-recurring congestion on freeways. Only recently has attention begun to focus on developing a methodology for surface street networks. The main focus of this research was to develop a methodology to detect different types of operational problems relevant to the operations of surface street networks. In this research, a modular architecture of neural network has been proposed to develop a comprehensive system to detect different types of operational problems, based on detector data from an urban traffic control system. The modularity of the classifier proposed decomposed the task of detecting different types of problems and produced an overall system of models that individually outperformed a single multi-layer feed-forward neural network model for lane-blocking incidents, special event conditions and detector malfunction, and also a statistically-based discriminant function model. The neural network-based models and the statistical models were developed and tested with simulated and field data from two test study areas in Anaheim and Los Angeles, California, USA. The higher detection rates and lower false alarm rates of the modular neural network model compared to other techniques demonstrated its potential of detecting different types of traffic operational problems on urban arterials.

Phd Dissertation

A microsimulation model for evaluating the environmental impact of alternative-fuel vehicles

Abstract

Despite recent improvements, Southern California experiences some of the worst air pollution nationwide. California has passed the strictest emission regulation in the nation to deal with the problem. The most controversial regulation mandates the sale of zero-emission vehicles: 2% of automobile sales by the major manufacturers must be zero-emission vehicles in 1998, 5% in 2001, and 10% by 2003. But simply mandating sales does not fully address the problem. Questions still remain: Under reasonable technological assumptions, what will the demand for alternative-fuel vehicles be? Will this demand greatly reduce emissions in Southern California? And if so, by how much? My dissertation addresses these important questions through the use of a dynamic microsimulation model. Microsimulation models begin with a sample of households or firms from the population. Each period the sample is faced with changing circumstances (such as the introduction of a new vehicle type), and their response is forecast based on models of their decision-making process. Since automobiles are a large consumer durable that must meet the needs of the entire household, when the household undergoes a demographic change, their vehicle needs will change. It is important to model household changes as part of the simulation process. In the first part of my dissertation, I develop demographic models which are used to simulate household changes. They extend previous models in three main ways: (1) by using continuous time hazard models, (2) by allowing for inter-dependencies across the various types of change that a household may undergo, and (3) by including several important explanatory variables such as race, gender, income, education, employment status, and indicators of previous demographic changes. I then run the microsimulation model under several different assumptions about the availability of alternative-fuel vehicles, vehicle prices, operating characteristics, fuel prices, and fuel availability. For each run, I determine total emissions using the forecasts of vehicles by vintage and fuel type, mileage estimates for each vehicle, and emission factors for each vehicle. I look at scenarios with different purchase price assumptions for electric vehicles, without the option of electric vehicles, and with different purchase price assumptions for CNG vehicles. Based on my comparison of the scenarios, I find that reducing the price of alternative-fuel vehicles does not necessarily lead to reductions in emissions. During the first few years, emission levels may actually increase if households trade off usage between a limited range alternative-fuel vehicle, and their second or third vehicle (which is typically an older gasoline vehicle). I also find that the option of electric vehicles leads to a definite and immediate improvement in emissions (or conversely, that removing the option of electric vehicles increases emissions). Using cost estimates from Small and Kazimi (1995), the health benefits of those emission reductions are valued at between $40 million and \$140 million. While a significant benefit, it is the same the magnitude as the United States Advanced Battery Consortium’s yearly research budget. Since the battery consortium’s budget is only a tiny fraction of the costs associated with the current electric vehicle mandates, the most prudent policy may be to abandon the current mandates for more cost effective policies.

Phd Dissertation

Citizens near the path of least resistance: Travel behavior of Century Freeway corridor residents

Publication Date

June 29, 1995

Abstract

This work joins a body of literature that tests whether commuting data support: (a) a hypothesized mismatch between employment or shopping opportunities among isolated groups of urban residents; and (b) the equitable distribution of mobility benefits following the opening of a major urban freeway. A history of the urban interstate system and the legislation guiding its construction is provided first as a background to the study. Second, a social ecological interpretation of the multi-dimensional effects of a change in urban form is introduced with a specific orientation toward freeway sitings. New highway impacts vary depending upon the condition of the surrounding area and proximity to the facility. Three grouping variables are introduced as possible means through which to categorize residents severely impacted by the construction of the Glenn M. Anderson (Century) Freeway/Transitway (Interstate 105). A behavioral measure segments residents based on the social and economic conditions in their census tracts. Two geographic grouping variables separate inner city residents from more suburban residents and residents close to the right-of-way from those more than a mile from the construction. U.S. Census data illustrate the social and economic differences among these groups within the Century Freeway corridor area. It is determined that, at an aggregate level, mean travel time to work is longer for residents of distressed areas, central city areas and residents near the right of way. Residents in the study area are surveyed at two points in time. Baseline travel behavior analyses indicate that controlling for race, education, income, and mode choice, the work trip of South Central Los Angeles residents is longer than neighboring areas in the corridor. Also, this trip is longer for residents living within one mile of the freeway. The behavioral variable does not aid in the discrimination of work trip travel times. Analysis of transportation behavior subsequent to the freeway opening reveals that the travel time savings for work and nonwork trips are unequally distributed across the study area. Significantly, the freeway opening is not associated with a convergence of work trip travel times. Those least affected by highway construction demonstrate travel benefits that are not found among severely impacted respondents.

Phd Dissertation

Studies in transportation and residential mobility

Publication Date

June 29, 1995

Author(s)

Abstract

Understanding travel and residential mobility behavior is crucial for formulating urban policies and planning urban infrastructure. These decisions shape urban structure, and may contribute to problems such as congestion, air pollution, urban decline, and urban sprawl. The first part of the dissertation examines differences in commuting patterns between men and women, as a function of differences in household composition and household division of labor. I find that single men and single women have similar travel patterns, but the travel patterns of men and women with families differ from each other. Gender differences are particularly important in making a side trip, but less so in mode choice and trip scheduling. They arise mainly from the differential effects of household composition on men and women. In particular, having children adds side trips to mothers, but not to fathers. Men are less likely to make a side trip when there is another adult in the household, especially when this adult does not work. But women do not seem to have a similar advantage. Women tend to ride with family when there is another adult in the household. The second part of the dissertation examines residential mobility, advancing the literature by: (1) using hazard models within a competing risks framework to model different types of moves; (2) using the individual as a unit of analysis; (3) accounting for undeserved heterogeneity; and (4) testing for effects of accessibility and neighborhood characteristics. The results establish important differences in the determinants of different types of moves. For example, any change in household income stimulates own-to-own, rent-to-own, and rent-to-rent moves; but only a decrease in income stimulates an own-to-rent move. Changes in household size are unimportant in rent-to-own moves, but they stimulate own-to-own and rent-to-rent moves. Only a decrease in household size stimulates own-to-rent moves. Wealthier households are more likely to move from owner-to-owner and renter-to-owner. Larger households are less likely to make rent-to-rent moves. Generally, renters are more likely to move. Age is important in determining rent-to-own moves: mobility initially increases until age 41, and then decreases. Job changes stimulate own-to-own and own-to-rent moves.

working paper

The Century Freeway/Transitway I-105: Nucleation, Land Use Changes and Transportation Behavior

Abstract

The Glenn M. Anderson Freeway/Transitway project includes six lanes for general traffic, two HOV lanes, and the Green Line, a light rail project with ten transit stations and park and ride lots. The 17.2 mile facility traverses eleven jurisdictions and serves these and other neighboring communities. The study analyzes transportation attitudes and behavior before and after the opening of both the freeway and before the transitway opening. We measure travel behavior impacts of the new transportation system using a panel study. The attitudes and intended use of the facility as well as a 24 hour travel diary. Also investigated land use around transit nodes and local freeway interchanges by measuring zoning changes, reviewing general plans and other documents, and interviewing local planning officials.

working paper

Regulation by Prices and by Command

Publication Date

May 31, 1995

Abstract

Standard economic theory states that regulation by price is more efficient than regulation by command and control. Exceptions may arise of regulators have good knowledge of the supply curve. In practice, though, governments usually regulate by command and control, and do so when there is uncertainty about the technology of supply. We show that government may prefer to regulate by command and control when it cares about the investment decisions of a firm.