bluuebunny/crossref_metadata_2025 huggingface dataset:
Motive, Opportunity, Choice, and Corporate Illegality
Authors: McKendall Marie A. , Wagner John A.
Published: October 2008

Research on corporate illegality spans several distinct literatures and defies ready integration. This article helps to overcome those problems. Analysis of data from 80 U.S. industrial organizations indicates that lower industry profitability is associated with higher frequencies of detected serious violations of federal environmental laws. Organizational profitability, industry concentration, organization size, structural complexity, organizational decentralization, and ethical climate join this variable in statistical interactions also associated with detected instances of serious environmental violations. However, none of those variables are found to be associated with the incidence of detected nonserious violations. These results provide qualified support for a model of corporate illegality in which illegal behaviors are attributable to the interactive effects of motive, opportunity, and choice. They suggest that illegal corporate activities resist simple explanation, and that future research on corporate illegality should concentrate on further development of multivariable models.
Perspective—The Infeasibility of Invariant Laws in Management Studies: A Reflective Dialogue in Defense of Case Studies
Authors: Numagami Tsuyoshi
Published: October 2008

The author questions the possibility of establishing invariant laws for social phenomena and presents an argument for the case study method. Despite the many alleged advantages of the case study method, its validity remains in doubt. Various concepts and techniques have been developed to make the method rigorous enough to meet the stringent criteria of nomothetical social science, but it often fails to meet two of them: (1) reliability and replicability, and (2) external validity. Those two criteria can be met only when social researchers find an invariant law. The author examines whether those two criteria are really necessary and attempts to clarify the conditions under which they are relevant, that is, the conditions under which an invariant law can be discovered in social phenomena. He argues that the conditions are so stringent that the search for an invariant law should not be the main objective of management studies, and he contends that reliability/replicability and external validity are irrelevant not only for the case study, but for any method of management studies. Without those two criteria, the validity of the case study can be forcefully reasserted. The author concludes by suggesting that serious consideration be given to whether the objective of management studies should be changed from a search for invariant laws of practical use to the encouragement of reflective dialogue in society.
Feeling Stressed and Burned Out: A Feminist Reading and Re-Visioning of Stress-based Emotions Within Medicine and Organization Science
Authors: Meyerson Debra E.
Published: October 2008

This article is written in the spirit of resistance, as a challenge and alternative to what are accepted as neutral, unbiased conceptualizations of stress and burnout within traditional and popular discourse. Findings reported in a previous study suggest that the ways we conceptualize and experience stress and burnout are not inherently neutral, but are shaped by culture and a particular set of dominant themes prevalent in organizational and professional discourse. This article exposes the processes by which some forms of organizational experience and knowledge related to stress and burnout have become dominant, whereas “other” forms have become marginal and suppressed. Through a postmodern feminist reading of stress and burnout as expressed within the medical and organizational discourses, the author reveals how gender acts as an axis of power and meaning that helps sustain dominant and seemingly neutral conceptualizations within the discourses. Building from the feminist reading, she develops a radical reconstruction of the ways organizational participants and theorists could interpret and experience stress related emotions, and discusses the cultural conditions that could produce and sustain such a revision. The reading and revision reveal ways in which experiences of stress and burnout have been shaped and constrained by the dominant discourse and suggest ways social scientists might rewrite those experiences toward more humane ends. Insofar as stress and burnout are among the most common and well-researched topics (and emotions) within the field of organizational behavior, this paper has far-reaching theoretical, epistemological, and practical implications. More generally, the feminist reading and revision open new spaces for other ways of theorizing and argues against the limitations of knowledge and experience imposed by traditional organizational theory and medical discourse.
Portfolio Restructuring and Limits to Hierarchical Governance: The Effects of Environmental Uncertainty and Diversification Strategy
Authors: Bergh Donald D. , Lawless Michael W.
Published: October 2008

The authors test whether acquisitions and divestitures are related to environmental uncertainty and diversification strategy. Drawing from transaction cost economics, they predicted that increases in environmental uncertainty would reduce a company's ability to manage its subsidiaries efficiently and would lead to divestiture. Conversely, they predicted that decreases in environmental uncertainty would enable a company to manage its subsidiaries more efficiently and would lead to acquisition. Those predictions were expected to be strongest for firms with intermediate levels of diversification, as such firms are believed to be the most difficult to manage efficiently. Repeated measures analyses of a panel of 164 Fortune 500 companies supported the predictions for highly diversified firms (e.g., unrelated businesses) only. Less diversified firms reacted to increases in uncertainty by acquiring and to decreases in uncertainty by divesting. The results suggest that the relationship between diversification strategy and portfolio restructuring depends on environmental uncertainty. In addition, the study findings imply that there may be limits in the hierarchy's governance efficiency in relation to market modes and that those limits may be affected by environmental uncertainty and diversification strategy.
Does Trust Matter? Exploring the Effects of Interorganizational and Interpersonal Trust on Performance
Authors: Zaheer Akbar , McEvily Bill , Perrone Vincenzo
Published: October 2008

A conceptual challenge in exploring the role of trust in interorganizational exchange is translating an inherently individual-level concept—trust—to the organizational-level outcome of performance. We define interpersonal and interorganizational trust as distinct constructs and draw on theories of interorganizational relations to derive a model of exchange performance. Specifically, we investigate the role of trust in interfirm exchange at two levels of analysis and assess its effects on negotiation costs, conflict, and ultimately performance. Propositions were tested with data from a sample of 107 buyer-supplier interfirm relationships in the electrical equipment manufacturing industry using a structural equation model. The results indicate that interpersonal and interorganizational trust are related but distinct constructs, and play different roles in affecting negotiation processes and exchange performance. Further, the hypotheses linking trust to performance receive some support, although the precise nature of the link is somewhat different than initially proposed. Overall, the results show that trust in interorganizational exchange relations clearly matters.
Framing Strategic Decisions
Authors: Nutt Paul C.
Published: October 2008

Forces that set in motion a strategic decision making process were uncovered from 352 strategic decisions. Decision making was initiated by claims from stakeholders that pointed out salient concerns and difficulties and prompted directions to be set that guided a search for ways to respond. The study identified the types of claims and directions that prompted action and how these claims and directions influenced decision making success, looking for best practices. Success improved when claims were performance based and when the search for alternatives was directed by agreed upon performance expectations. Success declined when claims and directions inadvertently limited search or framed the strategic choice as an action to be taken.
Strategies of Engagement: Lessons from the Critical Examination of Collaboration and Conflict in an Interorganizational Domain
Authors: Hardy Cynthia , Phillips Nelson
Published: October 2008

Many writers advocate interorganizational collaboration as a solution to a range of organizational and intersectoral problems. Accordingly, they often concentrate on its functional aspects. We argue that collaboration deserves a more critical examination, particularly when the interests of stakeholders conflict and the balance of power between them is unequal. Using examples from a study of the UK refugee system, we argue that collaboration is only one of several possible strategies of engagement used by organizations as they try to manage the interorganizational domain in which they operate. In this paper, we discuss four such strategies: collaboration, compliance, contention and contestation. By examining the stakeholders in the domain and asking who has formal authority, who controls key resources, and who is able to discursively manage legitimacy, researchers are in a stronger position to evaluate both the benefits and costs of these strategies and to differentiate more clearly between strategies that are truly collaborative and strategies that are not. In other words, we hope to demonstrate that collaboration between organizations is not necessarily “good”, conflict is not necessarily “bad”, and surface dynamics are not necessarily an accurate representation of what is going on beneath.
Crossroads—Mediating the Fact-Value Antinomy: Patterns in Managerial and Legal Rhetoric, 1890–1990
Authors: Eastman Wayne , Bailey James R.
Published: October 2008

In this paper, we provide an account of past trends and future possibilities in management theorizing that sharply departs from Barley and Kunda's (1992) powerful and troubling “cog in the clock” metaphor. In their important recent historical account, they interpret managerial theory as an ideology designed to uphold managerial control. The current paper extends Barley and Kunda's (1992) inasmuch as it shares their methodology of explaining developments in management theory as ideological responses to underlying contradictions. However, our history departs from theirs in several important respects that, taken as a whole, constitute a challenge to their work.
The Co-Evolution of Strategic Alliances
Authors: Koza Mitchell P. , Lewin Arie Y.
Published: October 2008

This paper proposes a co-evolutionary theory of strategic alliances. The paper proposes a framework which views strategic alliances in the context of the adaptation choices of a firm. Strategic alliances, in this view, are embedded in a firm's strategic portfolio, and co-evolve with the firm's strategy, the institutional, organizational and competitive environment, and with management intent for the alliance. Specifically, we argue that alliance intent may be described, at any time, as having either exploitation or exploration objectives. We further discuss how the morphology of an alliance—absorptive capacity, control, and identification—may be isomorphic with its intent, and, in the aggregate, drive the evolution of the population of alliances.
Learning from Failure: Towards an Evolutionary Model of Collaborative Ventures
Authors: Ariño Africa , de la Torre José
Published: October 2008

This paper reports on a longitudinal case study of the interaction between two partners to a failed international joint venture. We develop a model of the collaboration process in partnership and alliances based on earlier work by Ring and Van de Ven (1994) and by Doz (1996). We employ a series of events that occurred in the course of the relationship as the unit of analysis in order to trace the interactions between the partners, and to explicate the impact that external shocks have on their perceptions of efficiency and equity. The impact of these events, as well as the responses they elicit, on the quality of the relationship (and vice versa) are also considered. We find that the partners' assessments cause them to either engage in renegotiation of the terms of the contract, or to modify their behavior unilaterally, in an attempt to restore balance to the relationship. The process feeds back until a new mutual understanding of equity is restored, or else the relationship deteriorates gradually until a point when the venture is dissolved. We conclude that positive feedback loops are critical in the evolutionary process, that relationship quality is both an outcome and a mediating variable, and that procedural issues are critical from the start in fostering a climate for positive reinforcement and the building of mutual trust and confidence in the relationship.
Differential Learning and Interaction in Alliance Dynamics: A Process and Outcome Discrepancy Model
Authors: Kumar Rajesh , Nti Kofi O.
Published: October 2008

Our paper develops a dynamic theory of alliances by examining certain outcome and process discrepancies that may emerge as the partners interact, highlighting issues that are especially relevant in knowledge intensive alliances, such as joint R&D or product development. Firms enter into these types of alliances to create economic value and to acquire knowledge to enhance their competencies. The degree to which the partners can realize their objectives is dependent on their absorptive capacities and the collaborative strategies adopted by the partners. Outcome and process discrepancies may emerge as collaboration unfolds. Outcome discrepancies concern the ability of the partners to achieve their economic and learning objectives. Process discrepancies relate to the partners' satisfaction with the pattern of interaction, and affect their feelings of psychological attachment to the relationship. How the partners assess and react to discrepancies shapes the developmental path of an alliance. The alliance flourishes in certain states but may collapse in others as the collaboration is subjected to environmental changes or shifts in the grand strategies of the partners. Guidelines for assessing and managing outcome and process discrepancies are suggested.
The Alliances of Spin-Offs Versus Start-Ups: Social Ties in the Genesis of Post-Soviet Alliances
Authors: Sedaitis Judith
Published: October 2008

This paper links the alliance strategy of emergent firms to the structural relations in the network of new firm organizers. Data gathered in Russia from 1991 to 1993 on nine post-Soviet commodity exchange markets demonstrate how the difference in internal social structure between spin-off and startup exchanges shapes the strategy of their inter-firm networks and initial performance. The way in which managers come together structures their diversity and openness to the outside environment. In turn, the social structure internal to the firm affects the range and scope of their ties to other organizations. I show how the high range of overlap among the ties between spin-off founders has a more concentrated connection to the outside environment than the exchanges created by more loosely-linked startup founders. The relational costs of the more concentrated ties increases the cost of search, however, it lowers the cost of malfeasance. Thus, the model suggested proposes that the relative advantage of investing in relational capital is a double-edged sword which poses constraints along with its particular advantages. Finally, the model also brings to question the relative merits of concentrated alliances supposedly advantageous to new firms in particular by suggesting that conditions of transition and institutional instability may under-cut the relative advantage of familiarity and specialization found in Western settings.
The Impact of Joint Venture Status on the Longevity of Japanese Stakes in U.S. Manufacturing Affiliates
Authors: Hennart Jean-François , Kim Dong-Jae , Zeng Ming
Published: October 2008

A number of well-known studies report that between one-third and two-thirds of international joint ventures eventually break up. While many generalizations, explanations, and prescriptions have been based on these statistics, their meaning is unclear. First, all foreign affiliates are subject to normal business risk, and to the risk that they will be divested by parents for strategic or financial reasons. Are these risks higher for joint ventures than for wholly-owned subsidiaries? Second, joint ventures may be shorter lived not because of their joint venture status, but because affiliates which are joint ventured have other characteristics that make them more likely to exit. To know whether joint ventures are shorter lived, one must control for the other factors that affect the longevity of affiliates, whether wholly-owned or joint ventured. Third, many joint ventures contracts contain clauses that allow partners to sell their stakes to one another at specific intervals. Because they make exit easier, joint ventures should have shorter lives, but these shorter lives should only be due to selloffs, not to liquidations. It is therefore important to see whether the supposedly higher termination rate of joint ventures stakes is due to a higher rate of selloffs or to a higher rate of liquidations.

In this paper we (1) compare the longevity of stakes in joint ventures versus those in wholly-owned subsidiaries (2) while controlling for other factors that affect the longevity of such stakes and (3) while distinguishing between two types of exit, those through sale and those through liquidation. While past authors have addressed these three issues in piecemeal fashion, we believe we are the first to address them simultaneously. We analyze the factors that affect the longevity of 355 Japanese stakes in U.S. manufacturing affiliates. Controlling for all the factors that affect exit rates, we find that Japanese parents are more likely to terminate their stakes in U.S. joint ventures than in wholly-owned subsidiaries. This higher termination rate of joint venture stakes is explained by a higher probability of selling them, but not of liquidating them. Most of the other factors that have been found significant in explaining gross divestment of foreign affiliates do in fact only affect exits through sales, but not exits through liquidations. Hence it is true that joint ventures have shorter lives, but dangerous to interpret this finding as necessarily meaning that they are more likely to “fail”.
Varieties of Social Influence: The Role of Utility and Norms in the Success of a New Communication Medium
Authors: Kraut Robert E. , Rice Ronald E. , Cool Colleen , Fish Robert S.
Published: October 2008

This natural experiment investigates the introduction and use of a pair of competing video telephone systems in a company over a period of 18 months. Both quantitative, time-series analyses and in-depth interviews demonstrate that employees adopted and used the video systems for both utility and normative reasons. Consistent with utility explanations, people in the most communication-intensive jobs were the most likely to use video telephony. Consistent with social influence explanations, people used a particular system more when more people in general were using it and when more people in their work group were using it. There were two conceptually distinct, but empirically entangled, types of social influence. First, use by other people changed the objective benefits and costs associated with using the systems, and thus their utility. Second, use by others changed the normative environment surrounding the new technology. Both utility and normative influences were stronger in one's primary work group. Implementers, users, and researchers should consider both utility and normative factors influencing both the success and failure of new organizational communication systems.
The Influence of Relational Demography and Guanxi: The Chinese Case
Authors: Farh Jiing-Lih , Tsui Anne S. , Xin Katherine , Cheng Bor-Shiuan
Published: October 2008

Two studies were conducted to investigate the indigenous concept of guanxi and its applications in the Chinese context. Guanxi refers to the existence of direct particularistic ties between an individual and others. We relate the concept to the idea of relational demography, which refers to similarities or differences between an individual and others on such factors as age, gender, race, religion, education, and occupation. The two studies focused on the importance of guanxi and relational demography in Chinese employment settings. In study 1, their importance was examined in a sample of 560 vertical dyads (i.e., between supervisor and subordinate) in Taiwan. In study 2, the effects were analyzed in a sample of 205 horizontal dyads, specifically between business executives and their important business connections (e.g., key customers, suppliers, bankers, government officials) in mainland China. Results support the importance of both guanxi and relational demography for subordinate trust in the supervisor, but only guanxi is found to be (extremely) important for business executives' trust in their connections. Implications for future cross-cultural research on the effect of common ties are discussed.
Latecomer Strategies: Evidence from the Semiconductor Industry in Japan and Korea
Authors: Cho Dong-Sung , Kim Dong-Jae , Rhee Dong Kee
Published: October 2008

The effects of strategic order of entry on firms' performance have long been an issue in many areas of study. Past research efforts, however, have been concentrated mostly on first mover or early entrant advantages. To contribute to developing a theory of latecomer strategies, the authors investigate how latecomers compete successfully or even leapfrog early movers. They review previous studies on early mover advantages and disadvantages, and group the sources of such advantages or disadvantages into three areas: the firm, its market, and its competitors. The theoretical focus is how a firm converts the opportunities stemming from entry order into performance. The authors seek to confirm and extend relevant theories by examining how late entrants have caught up with incumbent industry leaders in the global semiconductor industry. On the basis of in-depth case analysis of three Japanese and three Korean semiconductor companies, they identify and categorize successful latecomer strategies into two types: strategies for overcoming latecomer disadvantages and strategies for utilizing latecomer advantages. Focusing, thin margin or loss bearing, and volume building form the essence of strategies for overcoming disadvantages, whereas odd timing, time compression, human-embodied technology transfer, benchmarking, technological leapfrogging, and resource leveraging form the essence of strategies for utilizing advantages. Because many companies in Asia have had to face the reality of being latecomers, the Asian perspectives are particularly useful for studying and explicating latecomer strategies.
Introductory Essay—Improvisation as a Mindset for Organizational Analysis
Authors: Weick Karl E.
Published: October 2008

The purpose of this essay is to improve the way we talk about organizational improvisation, using the vehicle of jazz improvisation as the source of orienting ideas. I start with two brief descriptions of the complexity involved when musicians compose in the moment. Then I review several definitions intended to capture holistically what is happening when people improvise. Next, I take a closer look at selected details in improvisation, namely, degrees of improvisation, forms for improvisation, and cognition in improvisation. These understandings are then generalized from jazz to other settings such as conversation, therapy, and relationships of command. I conclude with implications for theory and practice.
The Vancouver Academy of Management Jazz Symposium—Jazz as a Metaphor for Organizing in the 21st Century
Authors: Hatch Mary Jo
Published: October 2008

Mary Jo Hatch's introductory speech to participants of The Vancouver Academy of Management Jazz Symposium.
Unsung Heroes: An Interview with Steve Havlovic
Authors: Frost Peter J.
Published: October 2008

Behind every successful performance, such as was the jazz symposium at the 1995 Academy of Management Conference, are people who have worked long and hard to try to ensure that the event will come to fruition; who have solved tricky problems and improvised in a number of ways, so that the performers can do their craft with a maximum of opportunity to excel.

In the case of this symposium, organizing involved having very specialized microphones in place and in working order. It required getting all the right permits (some unanticipated) approved and it meant having an effective grasp of and control over the logistics of a complex process well beyond the prior experience base of most of the organizers involved. It meant doing these things at a ridiculously low price and yet operating at a cost that was higher than anticipated. New money had to be found, rules and laws had to be bent or reframed or reinterpreted. When the magic of the session unfolded, when people were learning, having fun and being moved by what they experienced on stage, it was due, in no small part, to the individuals behind the scenes who themselves had performed, learned and improvised and who thus had helped created conditions that enabled the event to take place. Such individuals often are unsung heroes. They have stories to tell that are interesting and instructive.

What follows are the recollections of one such hero, Steve Havlovic, Chair of the Local Arrangements Committee for the 1995 Academy of Management Conference in Vancouver, British Columbia, Canada. In conversation with Peter Frost, he talks about the roles that he and others who worked with him played in preparing the ground for the jazz symposium and he describes some of what happened along the way. The story provides a perspective on the way improvisation and organizing may be intertwined in both the figure and the ground of a novel event.
Working the Jazz Metaphor: Musings Driving Down I-5 Past Midnight
Authors: Berniker Eli
Published: October 2008

Applying unfettered but disciplined imagination to last night's Academy of Management 1995 session on the jazz metaphor, I asked: How would I design an organization as if it were a medium for improvisational jazz? I know that the design metaphor grates on some sensibilities. Bear with me. I am a tinkerer and bricoleur at heart. I write as thought emerged subject to minor editing.
Variations on a Theme—Practice Improvisation
Authors: Mirvis Philip H.
Published: October 2008

The author exposes various views on the apparently contradictory topic or practising improvisation.
Coda—Creativity and Improvisation in Jazz and Organizations: Implications for Organizational Learning
Authors: Barrett Frank J.
Published: October 2008

After discussing the nature of improvisation and the unique challenges and dangers implicit in the learning task that jazz improvisers create for themselves, the author broadly outlines seven characteristics that allow jazz bands to improvise coherently and maximize social innovation in a coordinated fashion. He also draws on his own experience as a jazz pianist. Finally, implications for organizational design and managing for learning are suggested.
Electronic Mail and Organizational Communication: Does Saying “Hi” Really Matter?
Authors: Sarbaugh-Thompson Marjorie , Feldman Martha S.
Published: October 2008

When people use electronic mail, they can communicate even when they are not physically or temporally proximate. Thus, it is not surprising that most studies report that the use of electronic mail increases organizational communication. In the study presented here, overall organizational communication declined as use of electronic mail increased. As we probed the nature of this decline, we discovered that much of the lost communication was greetings. This raises questions about the role that greetings, and other forms of casual conversation, play in an organization. To organize our insights about this topic we formulate a two-by-two communication matrix based on presence versus absence and availability versus unavailability. Prior research focuses on the ways being present and available and being absent but available through electronic mail affect the performance of specific communication tasks. Using our typology, we direct attention to the role of casual conversation in presence availability and to the parts that presence unavailability and absence unavailability can play in organizational communication.
On Spiral Road Networks
Authors: Miller Alan J.
Published: October 2008

The networks considered in this paper consist of ring roads and equiangle spirals rotating in both directions. Journey lengths and numbers of crossings of paths are found for a circular city with uniformly and independently distributed origins and destinations of trips. The 30° spiral-and-ring network gives an average journey length 18 per cent less than a 90°-grid and 5 per cent less than a ring-and-radial network for this city. The minimum number of crossings of paths is about 14 per cent less than would be obtained if drivers could travel in straight lines between origin and destination. This minimum is obtained with a 70° spiral-and-ring network.
Traffic Signal Synchronization on a One-Way Street
Authors: Bavarez E. , Newell G. F.
Published: October 2008

We consider a one-way street that intersects n one-way (side) streets. Traffic approaching the first street is steady as are the flows on all side streets. Traffic signals are idealized as perfect on-off switches and traffic is treated as a fluid moving with a constant velocity on the main street. Total delay and total number of stops are evaluated for several types of signal coordination schemes. Some conclusions are:

1. For any given common cycle time and given splits at each intersection, there is a choice of offsets (phases) that simultaneously minimizes both the total delay and stops, but it is not necessarily the one that produces a “through band” of maximum bandwidth.

2. There are signal settings for which some signals operate on half or a third the cycle time of other lights, which give a main street delay equal to that for the optimal common cycle time setting but give less delay to the side street.

3. Similar models are commonly used to find maximum through bands for two-way traffic, but it is not obvious that this is a suitable objective even for one-way streets.
A Model for Flowing Passengers Over Airline Networks
Authors: Gagnon Gilles
Published: October 2008

There are frequently several different ways in which passengers may fly from any one point to any other in an airline network. Passengers may choose a nonstop flight, a flight using the most desirable type of aircraft, a flight departing or arriving at the most convenient time, and so on. It is therefore necessary for an airline to plan many months ahead to obtain a flight schedule that will best answer the needs and desires of the traveling public. The Passenger Allocation Model has been designed and developed to assist in this planning process. It allocates a forecast volume of passengers, traveling from any point in the system to any other point, to the various flight paths offered by a proposed schedule. Decision rules are used that quantify the effects of such factors as the frequency of all flights between the two points, the times of arrival and departure of each flight, the types of aircraft to be used, the types of flights (direct or connection) and the number of seats available. This paper describes the general structure of the model.
Travel Patterns of Urban Residents
Authors: Kansky Karel J.
Published: October 2008

The impact of new and improved transportation facilities on urban travel behavior is a topic seldom addressed in transportation-research literature. The paper presents a method for classifying travel behavior of urban residents and suggests a procedure for quantitatively estimating diverted traffic. An application of the method is made to a limited sample of Chicago's residents. Seven groups of residents with similar travel patterns were identified and the impact of a new expressway on each of the seven groups was estimated. The study suggests a reorientation of research activities: in addition to the analyses of aggregate traffic data a greater attention should be directed toward detailed inquiries about the travel patterns of urban residents and the spatial structure of commercial traffic.
The Effect of the Interstate System on Short-Haul Air Passenger Demand
Authors: Scheiner James I.
Published: October 2008

When an interstate highway is completed between two cities less than 200 miles apart, some people find it more convenient to switch from air travel between the two cities to automobile or bus travel. This paper employs a multiple regression model to quantitively examine this effect of interstate highway construction on short-haul air market. Several techniques are used to isolate the impact of changing highway quality on the short-haul air market from a myriad of other influencing factors. The city-pairs chosen for the regression sample are all between 105 and 185 miles apart so that the distance variable is constrained. An “airport use” variable is introduced to reflect changing environmental demand determinants such as income and population. The regression is run in first difference form, which eliminates multi-collinearities as well as the influence of static factors. Finally, quarterly data is used rather than yearly data to provide more degrees of freedom, and quarters are compared with the same quarters in an earlier year to eliminate the effect of seasonal variations. The coefficients of the resulting regression indicate two important conclusions. First, short-haul air markets are growing only about half as fast as the air market as a whole. Second, a significant number of travelers do switch from airplane travel to automobile travel when an interstate highway is made available for a one hundred to two hundred mile trip.
Optimal Control of Oversaturated Store-and-Forward Transportation Networks
Authors: D'Ans G. C. , Gazis D. C.
Published: October 2008

A general method is developed for the dynamic optimization of multi-commodity flows in an oversaturated, store-and-forward transportation network. The network is characterized by time-varying inputs, and the existence of queues in front of certain nodes where the incoming flows exceed the capacity to discharge them, during a certain period of oversaturation. The method consists of discretizing in time and solving a linear programming (LP) problem, in order to obtain the order of exhaustion of the various queues and an approximation to their, optimum time variation. The LP solution may be refined to any degree of desired accuracy, or used as a first step in a two-step procedure, where the order of exhaustion of the queues of the LP solution is used in a variational scheme to obtain the exact solution. The method is demonstrated by optimizing the operation of a two-node, four-queue network.
The Influence of Forward Vision and Target Size on Apparent Inter-Vehicular Spacing
Authors: Evans Leonard , Rothery Richard
Published: October 2008

When one car follows another, the driver of the following car makes spacing judgments based on observing the lead ear within his field of vision. This visual field depends on a variety of design features of the following car, such as hood geometry, and is difficult to quantify simply. One quantity which relates to the driver visual field is the amount of roadway obscured from his view by his automobile. It is possible that the amount of this obscuration could influence spacing judgments. Furthermore, it is possible the size of the lead car, as characterized by the rear bumper length, might influence, spacing judgments. A laboratory experiment using color slides was devised to investigate if the amount of forward obscuration or target size influenced apparent spacing. The color slides showed the view of a driver seated in one car following another. Two different models of cars, with different values of forward obscuration and target size, served as lead and following cars. The influence of forward obscuration was also investigated by elevating the rear of one of the following cars. It was found that the lead ear target size did not systematically influence apparent spacing. On the other hand, changes in forward obscuration, whether caused by different following cars, or by elevating the rear of the same car, did influence apparent spacing; the same spacing appeared greater for smaller forward obscuration. These findings are related to reported test-track results.
Some Issues Relating to Metering or Closing of Freeway Ramps Part II. Translationally Symmetric Corridor
Authors: Allen Brian L. , Newell Gordon F.
Published: October 2008

As an idealization of a long freeway imbedded in a network of parallel streets, we consider a hypothetical freeway with equally spaced entrance and exit ramps joining an adjacent slower speed parallel route. The origin-destination pattern of trips is assumed to be translationally symmetric on the adjacent route. Each ramp can be metered (causing a queue to form), closed, or left uncontrolled. Two extreme strategies are considered. In the first, the ramps have a spacing short compared with the average trip length, but all ramps are metered at the same rate. In the second, the spacing between ramps is adjusted by closing ramps, but those which are open are not metered. Flow on the freeway is reduced because travelers will (on the average) travel a certain fraction of their journey on the alternate route, enroute to a ramp. The latter strategy typically gives a lower total travel cost, for flows on the freeway close to its capacity.
Statistical Aspects of Injury Severity Part I: Comparison of Two Populations When There Are Several Grades of Injury
Authors: Hutchinson T. P.
Published: October 2008

A method is proposed of comparing the average levels of injury sustained in two conditions. It consists of plotting the proportion of cases in one population that exceed an arbitrary threshold of severity against the proportion of cases in the other population that exceed the same threshold, as the threshold varies. The further this curve is from the 45 degree line, the greater is the difference in severity between the populations. The precise shape of the curve depends on the particular model considered: two examples are derived from considering the distributions of injury severity, respectively, each to be (i) normally distributed with the same variance, or (ii) exponentially distributed; the means of the distributions differing. A number of applications of this type of theory are outlined.
The Unpublished Schedule of Urban Peak Period Traffic
Authors: Sparks Gordon A.
Published: October 2008

Urban peak period traffic is unique in that a significant portion of all trips are made by persons making daily trips to and from work. The effect that such an underlying daily schedule may have upon the stochastic properties of urban traffic demand is discussed, and the existence of such a schedule is investigated empirically for five locations.
Books of Interest
Authors: Orloff Clifford S.
Published: October 2008

A review and recommendation of the book Automated Techniques for Scheduling of Vehicle Operators for Urban Public Transportation Services, bound papers of a workshop held April 27–29, 1975, in Chicago, Illinois, sponsored by Transportation Science Section (O.R.S.A.), Office of Transit Management (U.M.T.A.), and Technology Sharing Program (Transportation System Center), 500 pages, available from O.R.S.A., $15.
An Abbreviated Procedure for Estimating Equilibrium Queue Lengths in Rural Two Lane Traffic
Authors: Gipps P. G.
Published: October 2008

On two-lane two-way roads overtaking opportunities are limited by the opposing traffic. For fixed volumes of traffic in both directions the opportunities for vehicles in one lane to overtake depend on the mean length of queues in the second lane, so that the mean queue length in the first lane is a function of the mean queue length in the second lane and vice versa. This paper takes an earlier procedure for determining the mean queue lengths in the two lanes at equilibrium and simplifies it by assuming that the distribution of queue lengths is known. The results,obtained by assuming that the underlying distribution is Miller, Borel-Tanner, or geometric are then compared by a numerical evaluation.
An Application and Validation of Equilibrium Trip Assignment Methods
Authors: Florian Michael , Nguyen Sang
Published: October 2008

We describe an application of an equilibrium trip assignment method to the 1970 road network of the City of Winnipeg, Manitoba, Canada. We discuss in detail the validity of the method. The results are encouraging and demonstrate the suitability of the method for planning purposes.
Letter to the Editor—A Further Note on a Minimax Location Problem
Authors: Morris James G.
Published: October 2008

Elzinga and Hearn (Trans. Sci. 7, 100–103) have presented a simplified formulation of a multifacility location problem with rectangular distances as a linear program. This paper describes a further simplification which permits a closed-form solution. It is shown that the former simplification can be beneficially used to solve a different version of the problem.
Railyard Modeling: Part II. The Effect of Yard Facilities on Congestion
Authors: Petersen E. R.
Published: October 2008

After previously demonstrating that queueing models could be used to describe the classification, connection and train assembly operations in railyards, here is described how the service rates for these operations can be related to the physical characteristics of the yard and the traffic handled. Based on the number of classification tracks, the configuration of switching leads, the available yard engines, the marshaling rules and the traffic intensities, the switching workload is estimated. From unit operating times for these switching operations, the rates at which trains can be classified and assembled are calculated. These rates are then modified by standing capacity limitations of the yard. An example of the use of the model is presented.
On Vehicle Automatic Longitudinal Control
Authors: Fenton Robert E. , Chu Patrick M.
Published: October 2008

The achievement of safe and efficient longitudinal control is probably the most significant technical problem associated with individual-vehicle, automated transport systems. One aspect of such control the design, implementation, and onroad testing of an individual vehicle controller—is of concern here. The realized controller is characterized by small, online position errors (<1 ft position demotion) in both small- and large-signal input situations, passenger ride comfort (|J| < 1.6 ft/sec3 in online operations), and an insensitivity to both external disturbances and variations in key vehicle parameters. In essence, the designed controller is an attractive candidate for implementation and, at the very least, indicates the type of longitudinal performance one can expect from a realistically designed controller over the speed range 0–93 ft/sec.
Letter to the Editor—Fuel Consumption and Right Turn on Red: Comparison between Simple Model Results and Computer Simulation
Authors: Chang Man-Feng , Evans Leonard , Herman Robert , Wasielewski Paul
Published: October 2008

In a recent presentation, Lieberman and Cohen (Lieberman, E. B., S. L. Cohen. New technique for the evaluation of urban traffic energy consumption and emissions. Presented at the 55th Annual Meeting of the Transportation Research Board, Washington, D.C., January 20, 1976. Transportation Research Record, in press.) calculated the effect on fuel economy and emissions of permitting a right turn on red at signalized intersections. They applied a detailed computer simulation to a network of streets in Washington, D.C. Fuel consumption was obtained by adding up the fuel used to execute each individual maneuver. It is the purpose of this note to point out that, once the change in the average speed in a traffic system has been determined, the change in fuel consumption can be immediately derived using a simple model of the dependence of urban fuel consumption on average traffic speed without the necessity of performing the detailed fuel summation.
The Accuracy of Estimates for the Performance Criteria in Certain Emergency Service Queueing Systems
Authors: Halpern Jonathan
Published: October 2008

Several available models for urban emergency services, and in particular the hypercube queueing model, assume that the service time is independent of the locations of the call for service and possibly the dispatched unit. The effects of this assumption on the accuracy of the estimates for the system's performance criteria are investigated for a simple two-servers, two customers system. A modified, more accurate approximation method is suggested for such a simple system.
A Min-Max Theorem for p-Center Problems on a Tree
Authors: Shier D. R.
Published: October 2008

This paper considers the problem of locating p facilities on a tree network in order to minimize the maximum distance from a point on the network to its nearest facility. Such a problem might arise, for example, in optimally locating a fixed number of fire hydrants along a street network. The present, paper identifies an underlying min-max theorem that governs such a p-center problem. More specifically, this p-center problem is shown to be equivalent to the “dual” problem of locating p + 1 points on the network so as to maximize the minimum distance between pairs of points.
Parameter Estimation and Sensitivity of Parameter Values in a Flow-Rate/Travel-Time Relation
Authors: Taylor M. A. P.
Published: October 2008

This paper describes a new method for the estimation of parameter values in the Davidson flow-rate/travel-time relation. The method enables simultaneous least squares estimates of the model parameters to be found from observed data. Adaptions of the method may be made for cases where a value of one or other of the parameters is known previously. Further results about the reliability and sensitivity of the estimates can be obtained using results from the theory of linear statistical models. These results may be applied to a wide range of applications given assumptions about the covariance structure of the model errors (observed value-predicted value). A number of examples and applications of the basic method are described. Test data concerning vehicle travel times on an arterial wad shared with trams are analyzed. Some possibly useful results about the model parameters are found for this situation.
Book Reviews
Authors: Wigan Marcus R.
Published: October 2008

Traffic Equilibrium Methods, M. A. Florian, ed., Lecture Notes in Economics and Mathematical Systems, Vol. 118 (Proceedings of the International Symposium Held at the Université de Montréal, November 21–23, 1974), Springer-Verlag, New York, 1976, 432 pp—reviewed by Marcus R. Wigan.
Books of Interest
Authors: Yagar Sam , Daganzo Carlos F.
Published: October 2008

Review of books: (1) Proceedings of the Seventh International Symposium on Transportation and Traffic Theory, T. Sasaki and T. Yannaoka (Eds.), The Institute of Systems Science Research, Kyoto, 1977, 944 pages; (2) Mathematical Models: Mechanical Vibrations, Population Dynamics and Traffic Flow, Richard Haberman, Prentice-Hall, Englewood Cliffs, New Jersey, 402 pages, $18.95.