Line haul interstation spacing for low cost feeder modes

The choice behaviour of low cost travel (LCT) modes is very sensitive to travel distance. A line haul system designed on the basis of current planning practice of locating widely spaced stations to cater auto and bus feeder modes with the primary objective of gaining travel speed is hostile to non‐motorized and low cost feeder modes. With the revival of interest in promoting the use of walk'n ride and bike'n ride modes, there is a need to develop an appropriate tool to examine the effect of their specific characteristics in establishing the number and location of stations.

A generic normative behavioural hybrid model for locating the cost minimizing number and location of stations is developed for an LCT‐fed line haul system. The model considers the system with many to many two dimensional line haul demand density function in which the density varies in both x‐ and y‐directions. The feeder mode choice behaviour is incorporated in the model by integrating probability‐access/egress distance function with the objective function. Explicit functional relationships among the parameters of these feeder modes such as modal share as a function of access/egress distance with the parameters of line haul systems are developed. Dynamic programming is used to minimize the system cost. The generic model is shown to collapse into several simplified models capable of yielding approximate solutions for several well known special cases. It has been shown that location of stations is sensitive to the through load on board as well as users’ cost that defines the choice behaviour at large. Numerical examples are presented to demonstrate the applicability of the model.     

Marine log transportation and handling systems in british columbia: Impacts on coastal management

Abstract

Over 90 percent of British Columbia's annual log harvest enters into complex water‐based systems of transportation, storage, and handling. These systems have considerable impacts on a wide range of coastal resources and uses. A number of site‐specific conflicts have arisen between forestry and preexisting or emerging values including fisheries, mariculture, recreational boating, and harbor redevelopment. Specific data on the impacts leading to conflict are often fragmentary. However, concerns about highly valued and fragile areas‐particularly estuariesalong with industrial concerns regarding log losses and handling efficiency, have prompted changes in log handling. These include moves to dryland sorting, log bundling, and a redistribution of forestry activities in estuaries to accommodate other values. Conflict adjustments and responses have in the past been largely ad hoc and attempted in a jurisdictional vacuum concerning control of coastal management. A more inclusive strategy is now slowly emerging, which involves the coordinated participation of federal, provincial, and industrial interests.     

Book reviews

Improving Railway Financial Performance. By M. E. Beesley and P. B. Kettle. (Aldershot: Gower, 1985.) [Pp. 108.] £15–00.     

Transport innovation and passenger needs — changing perspectives on the role of Dial‐a‐Ride systems

The changing role of Dial‐a‐Ride systems in the period 1969 to 1985 is reviewed as a case study in transport innovation. The first phase Dial‐a‐Ride systems were conceived and planned as transport services to complement and even replace conventional transit. However, their failure to attract any sizeable part of the public transport market combined with their high operating costs led to their demise in the mid‐1970s, to be superseded by the second phase Dial‐a‐Ride systems as paratransit services to the elderly and handicapped. These later systems were often initiated by community‐based transport agencies which have demonstrated their ability as transport innovators in meeting passenger needs. It is suggested that other transport services could learn valuable lessons from the experiences of community Dial‐a‐Ride, and that Dial‐a‐Ride itself will prove historically to be an important transitional agent in the reorganization of passenger transport services in the post‐deregulation environment of the late 1980s and 1990s.     

A review of parking lot design models

The efficient design of parking lots is an important element in the development of the transport infrastructure. The design process often adopted is based on broad measures of parking demand, design manuals outlining the minimum size of the components and the experience of the designer. This process may not result in the best design. It is of particular concern that this process does not provide any quantitative information on the ‘level of service’ resulting from the choice of a parking layout. Models of parking systems provide this assistance. Existing models provide information on the utilization of the parking system, its capacity, the best distribution of parking space use and the delay experienced by parkers. Recent improvements in these models have been aided by rapid developments in computer and graphics technology. This paper reviews developments in models of parking lots.     

Inland boundary determinations for coastal management purposes—an ecological systems approach to requirements of the federal coastal zone management Act of 1972

Abstract

An analysis of ecological systems that both sustain and are sustained by coastal waters provides the key to a biophysical procedure for delineating inland coastal management boundaries. This analysis entails two basic tasks: (1) mapping the ecosystems that compose coastal waters and adjacent areas, and (2) charting sustaining flows among these systems. The resulting boundary encompasses all environments of coastal waters (subaqueous areas containing a measurable quantity of seawater) and all shore‐lands (either emergent or submergent environments that interchange sustaining materials, energy, or biota with coastal waters). As this biophysical procedure depends on the precise location of, and functional transfers among, coastal ecosystems, it provides a means both for assessing the consequences of human actions and for establishing a landward boundary for a management program. Alternative boundaries not based on locations and operations of coastal ecosystems would probably be either arbitrary or of undue extent, nor would such “alternative”; boundaries be an integral part of an ongoing management process.     

Comment

We welcome the opportunity to respond to the issues raised in your critique to our paper. We take the comments as an indication of the interest the paper has sparked. Not often is shipping in the Caribbean a subject of academic concern and we are pleased to keep it in the spotlight. Let us deal with the issues in the order that they are raised.     

The Quiet Revolution in Visual Resource Management: A view from the coast

Abstract

This introductory piece traces the growth of knowledge and activity associated with visual resource management in general. A specific framework of questions regarding methods of coastal zone visual resource management is presented. The state‐of‐the‐art in methodological studies is listed for each question, and the methodological questions are related to the major articles with the special issue of the Coastal Zone Management Journal. Major legal federal statutes, state statutes, and court cases are reviewed in light of visual resource management in the coastal zone. The remaining articles within the special issue that deal with integration of VRM into decision‐making are then arrayed against a management framework. This framework includes regulatory situations for (1) public land management and planning, (2) public projects involving private lands, and (3) public regulation of private projects.