Leon N. Moses

Value of Time, Choice of Mode, and the Subsidy Issue in Urban Transportation

The last two decades have clearly shown that increased automobile ownership and highway construction can facilitate profound redistributions of population and economic activity within metropolitan areas. These changes are related in a fundamental way to many of the social and economic difficulties of our large, mature, central cities: loss of middle and upper income groups to the suburbs, declining retail sales in downtown areas, erosion of the tax base, shift of manufacturing and service establishments to suburban areas, decline of mass transit service and patronage, and increased traffic congestion. There is a great deal of support for the view that there has been too much highway construction and that the time has come to help public transportation. This paper explores some of the issues involved in a program of assistance to public transportation.

The effect of firm characteristics on truck accidents

This paper expands an earlier analysis of the effect of firm characteristics and safety practices on truck accident rates. The sample size has been increased from 13,000 to 75,500. Negative binomial regressions are used in preference to the Poisson technique used previously. The current analysis confirms previous results, but provides important new insights into the safety implications of being a private carrier and hauling hazardous materials and the effect of having been in business for many years.

A General Equilibrium Model of Production, Interregional Trade, and Location of Industry

T HIS paper contains a model that emphasizes the intimate connection between interregional trade and the location of economic activity. The author has blended input-output and linear programming techniques in order to achieve substitution and optimization within a general equilibrium framework. What emerges is a multi-region, multi-commodity, empirical study in comparative advantage. To the authors knowledge, it is the first such study. The Census regions of the United States are the areas analyzed. However, the model can be applied to most groupings of regions for which transfer costs rather than artificial restrictions are the major impediments to trade. It also seems likely that a related approach could contribute to understanding the problems of adaptation which confront members of the European Common Market and other contemplated economic unions. As mentioned above, the model synthesizes two approaches to interregional analysis: linear programming as applied to transportation problems, and regional input-output methods. These two techniques have been applied to quite different problems in the past. Three things are taken as given in the typical linear programming transportation study: (i) quantities of a specified good that are available at a number of originating points; ( 2) quantities of the good that are required at a number of destinations; (3) the cost of transporting a unit of the good from each origin to each destination. The problem is to find a network of trade which will satisfy the requirements with a minimum total expenditure on transportation. Thus, the transportation model concentrates on an individual good and sDecifies nothingz so far as interindustry relationships are concerned. It begins with known regional production and consumption and determines the network of trade for a specified good. Regional input-output techniques emphasize the interconnections between industries. Their aim is to determine outputs and requirements of all goods in all regions. To accomplish this, these studies have found it necessary to make assumptions regarding patterns of trade. In one way or another they have treated trade patterns as a datum. It is precisely this aspect of regional input-output analysis that is changed in the present study. Trading patterns as well as regional outputs and requirements of all goods are determined. The model involves the introduction of alternative production techniques and substitution into input-output analysis. This substitution takes place between regions. However, the model can be adapted to permit substitution between industries and between different technological layers of the same industry. The paper is divided into three sections. The first contains a description of the basic model. The second contains a brief explanation of the data and computational difficulties and how these difficulties were overcome by making adjustments in the model. The final section contains some of the empirical results and an analysis of these results. Thus, the first section will help the reader to comprehend more readily the empirical analysis and the reasons behind some of its restrictive assumptions. It also brings to light certain important issues which the empirical analysis must ignore. The second section, on the other hand, will help the reader to understand the process whereby the conceptual scheme was converted into an empirical study.

Mode choice, transport structure and urban land use

Abstract A theoretical model of the urban land market is solved to examine the impact of bimodal passenger transportation on equilibrium residential land use. In this model travel to the central business district occurs on a dense system of radial roads or bus routes and a competing system or radial expressways or mass transit lines fed by a subsidiary system of densely spread access streets. Under rational behavior assumptions for households, it is shown that various basic urban forms can result depending on the relative generalized cost characteristics of the competing dense and sparse radial networks. The basic urban forms yield fundamental shapes, differing as to the relative geometry and position of the market areas for the two modes. The standard Alonso-Muth model of unimodal travel and circular urban form is found to result as a special case in several of these cases. American urbanized areas of various sizes and modal mix provide plausible examples for each of the basic forms. The paper concludes with a discussion of the models implications as a framework for examining optimum urban transport structure and the proliferation of transport routes as a function of urban size.

THE EFFECTIVENESS OF MOTOR CARRIER SAFETY AUDITS

In 1986 the federal government expanded its program of company inspections for enforcement of motor carrier safety regulations. We find that many parts of these inspections are unrelated to the safety performance of firms. Never the less, reinspection of firms found to be unsatisfactory in a previous inspection does appear to bring about a substantial improvement in their safety performance. However, such firms represent a small fraction of the industry, and the probability of being inspected is very low. Thus, the program does not appear to have resulted in a detectable improvement in the accident rate of the industry.

Interdependence and the location of economic activities

Abstract This paper deals with the ability of a decentralized price system to sustain an optimal assignment of activities assuming complete interdependence among them. There are two goods, each of which is used in its own production and in the production of the other, along with land. An infinitely elastic final demand exists for both goods at given market prices, and either good may be imported. It is demonstrated that a decentralized price system will sustain an optimal allocation of land, and that a nonoptimal allocation of land will not be sustained.

Qualitative Choice and the Blending of Discrete Alternatives

This paper takes a fresh look at discrete choice theory by observing that decision makers can deliberately blend discrete alternatives within an extended planning honrzon. Multinomial logit and generalized probit models are developed and their properties examined. These are then estimated and compared to the traditional myopic model using the travel diaries of a sample of commuters from Seoul, Korea. The new models yield travel cost elasticities which are substantially lower than those of the traditional approach.

A model of the firm in time and space

Abstract We consider a multi-plant monopoly that sells to markets which are geographically separated and which stores product over time via an inventory capability. It is assumed that plant average production cost is U-shaped and that, if the output of a plants production run were sold to a single market at only one point in time, the plant would operate on the falling portion of its average cost curve. Hence, it is in the interest of the firm to aggregate markets, both spatially and temporally, to lower average production cost. We develop the optimal joint interplant spacing-inventory policy. We also consider the effects changes in freight costs, storage costs, and interest charges have on the firms optimal policy.

Inventory investment, product cycles, and the imperfectly competitive firm

We consider a profit-maximizing, imperfectly competitive firm, with downward-sloping demand functions, that can produce multiple products at a single facility. We show that if the firm dedicates production to a single product, both dynamic production, which exploits inventory, and static production, which does not, can be optimal. We also consider sharing the production facility by multiple products. We evaluate the efficiency of scheduling production using simple rotation cycle scheduling, and give a condition for guaranteeing optimality of this scheduling rule. We conclude by studying when dedicated production is preferred over shared production.

Annual license fees and other charges for road transportation of hazardous materials

In September 1992 the United States Department of Transportation imposed a