Showing papers on "Fleet management published in 1983"

Vehicle Fleet Composition

Abstract: In this paper we consider the problem of determining the optimal composition of a vehicle fleet (i.e. the best fleet size and the best fleet mix). A literature review is given and a new formulation of the problem is presented.

Improved lower bound to the minimum fleet size problem

Abstract: The authors give a formal proof that a procedure to find a starting fleet size is a lower bound on the minimum fleet size problem when deadheading trips are allowed. It is shown that this bound is stronger than the "simultaneous operation" bound used previously by the authors in the URDHC program. The URDHC program is an interactive bus scheduling program which inserts deadheading trips into a timetable in an effort to reduce the required fleet size. The "simultaneous operation" lower bound is equal to the maximum number of trips in a given timetable that are in simultaneous operation over the schedule horizon. The improved lower bound is based on the construction of a temporary timetable in which trips are extended to include potential linkages reflected by deadheading time considerations.

The Effects of an Iron Based Fuel Catalyst upon Diesel Fleet Operation

Abstract: This paper will discuss several aspects of fuel combustion in internal combustion engines. It will be shown that one area of significant potential cost reduction for the operator of a major diesel fleet could involve the application of a chemical fuel catalyst to improve the combustion of the diesel fuel. It will be shown that substantial reduction in engine deposits and increased fuel economy on a long term fleet basis have resulted from the use of the catalyst in several large fleets operating in Western Canada.

The garage constrained - balanced vehicle schedule minimum fleet size problem

Abstract: The problem of finding the least number of vehicles require to service a given schedule of transportation trips is the minimum fleet size problem. The first part of this paper reviews two common approaches to solving this problem (with and without deadheading): 1) the deficit function approach, and 2) the well known Ford and Fulkerson array labelling technique. In the second part of the paper the problem is extended to include garage limitations and balanced schedule constraints. This development is pursued first as a problem in deficit function theory, and secondly as a mathematical programming problem. A simple solution procedure is suggested for a special case. For the covering abstract of the symposium see TRIS 452544. (TRRL)

The practical and economic considerations of converting highway vehicles to use natural gas as a fuel

Abstract: The costs of converting to CNG include vehicle conversion costs, refueling station costs, and required operating and maintenance costs. These costs vary according to vehicles (how many storage tanks and how difficult the conversions are), the planned utilization of compressor capacity, whether the vehicles are refueled using slow-fill or fast-fill techniques and the refueling site preparation required. In this paper, these costs are explained and compiled for the conversion kits and refueling equipment presently available. A few case studies are explored to demonstrate what must be known to evaluate whether a fleet of vehicles has potential to save money using natural gas and how long it may take to see a return on the initial investment. Also discussed in the paper is an overview of CNG safety aspects, especially as related to road and operating restrictions that may exist in some local jurisdictions. Thus, in keeping with the intent of this paper to be a practical guide for decision-makers, reference is made to safety-related considerations and the restrictions which may be imposed by some states or municipalities on CNG vehicle operation.

Vehicular fuel-consumption maps and passenger vehicle fleet projections

Abstract: The procedures and preliminary results of a study aimed at assessing the fuel-consumption characteristics of passenger vehicles that are representative of the current and near-future fleet in order to update the fuel-consumption models of computerized traffic simulation and optimization programs are presented. The paper identifies 21 engine-drivetrain combinations that are representative of 74 percent of the 1979-1985 passenger vehicle fleet and describes an instrumentation system that permits the collection of the microscopic on-the-road and laboratory test data necessary to fully assess the real-world fuel-consumption characteristics of vehicles. (Author)

Mobility enterprise: one year later

Abstract: A mobility enterprise is a new transportation concept aimed at increasing the productivity of the automobile through use of mini or micro automobiles in conjunction with a shared fleet of intermediate and full-sized vehicles. The main objective of the enterprise is to provide a better matching of vehicle attributers to trip requirements and still maintain the personal freedom that appears to be so highly valued by the American driver. Although this concept was presented in detail in an earlier TRB Record (TRR 882), a view of the progress that has been made in taking the mobility enterprise from an innovative concept to an actual experiment is presented in this paper. The majority of the information deals with methods for observing consumer attitudes, designing the actual mobility enterprise, and measuring mini and micro automobile performance.

JETFOIL - The Wave of the Future

Abstract: JETFOIL is presented as a hydrofoil with unique capabilities operating world-wide, year-around as a high speed transportation system. A brief historical summary of the JETFOIL program is discussed as well as where the hydrofoils are in-service and the achievement of high fleet reliability. The configuration features of Boeing hydrofoils such as foil arrangement, automatic control, gas turbines and waterjet propulsion are discussed as they affect the specific hydrofoil attributes of speed, ride comfort and agility. Present and future JETFOIL applications in the role of resource protection, offshore transportation, and naval coastal patrol are also presented.