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From time to time, over many years, MIRA (the Motor Industry Research Association) has carried out surveys of the handling behaviours of various classes of road vehicles. The most recent investigation has concerned modern European intercity buses, or coaches as they are termed in Britain. The work was sponsored by the British Government together with five vehicle manufacturers who each supplied one bus. The main aim of the work was to ascertain the handling characteristics of a sample of modern buses in terms of both absolute behaviour and relative behaviour compared to other classes of road vehicles. However, the manufacturers sponsoring the work were also very interested to discover any correlation between various features of layout of the vehicles and the handling characteristics.

New communication and information processing technology is significantly changing the world of logistics and transportation. A new program established by the U.S. Department of Transportation, known as the Intelligent Vehicle-Highway System (IVHS) Program, seeks to apply this technology to transportation in an organized fashion. The goal is to improve the efficiency and safety of the highway system. Many of the new technologies have the potential to allow the automation of the hazard communication process during hazardous material transportaiton. This paper identifies and discusses some of the potential applications of IVHS technology to the hazardous material transportation environment.

This paper reviews the history of heavy truck noise legislation in the U.S. Both legislative activity and the response of vehicle and engine manufacturers are described. The cost cycle experienced by manufacturers is also described. Over a period of time, the costs involved in meeting noise regulations are reduced without increasing truck noise levels. Data is presented which shows that public complaints about truck noise are often related to modified vehicle exhaust systems. The data shows that modified exhaust systems have an especially severe effect on compression brake noise. Additional results suggest that some trucks with extensively modified exhaust systems may be able to pass the in-use noise standard.

In January 1989, the California Energy Commission called on engine and coach manufacturers to identify the concerns and obstacles to be overcome in order to develop a School Bus Demonstration Program using alternative fuels. Working closely with Detroit Diesel Corporation, Crown Coach undertook the development to apply DDC's methanol-fueled 6V-92TA engine in the Crown transit style heavy-duty school bus. Safety was the prime consideration in designing a vehicle that not only exceeded FMVSS-301 Fuel System Integrity requirements and State specifications, but also met the anticipated needs of the operating school districts and potential concerns of parents.

In late 1996, Daimler-Benz together with WABCO and Scania together with Bosch presented the first electronically controlled brake systems (EBS) in their towing vehicles. Since then roughly 2000 ACTROS per month have been produced with EBS. Other vehicle manufacturers will introduce EBS in the near future [5]. The technical advantages of EBS combined with the increased application of disc brakes, are: improved safety through shortened stopping distance better vehicle stability and brake comfort optimized brake monitoring and higher profitability However, with this first step the technical possibilities are limited to towing vehicles combined with conventionally braked trailers. The overall braking performance of the combination unit can be further improved when the trailers are equipped with an electronically controlled brake system.

The active safety of tractor / trailer-combinations plays an important role in regard to traffic safety in general. For improving the active safety of tractor / trailer-combinations, it is necessary to investigate the interactions between the towing vehicle and the trailer during braking maneuvers. This paper describes the ECE-regulations for the braking force distributions of tractor/full trailer- and tractor / semitrailer-combinations. The influence of different layouts of the braking systems within these regulations on the coupling forces between tractor and trailer and the driving performance of the units during braking is investigated. The dynamical behaviour of a tractor/full-trailer-combination and a tractor / semitrailer-combination are both discussed with the aid of simulations of the ISO-standard testing procedures “Braking in a turn” and “Braking straight ahead”.

Technologies and incremental costs for meeting the proposed 2004 US emissions standards for heavy-duty diesel engines are discussed in this paper. Manufacturers will most likely use a combination of technologies including reoptimized combustion chambers, fuel systems, air handling systems, electronic controls and aftertreatment. First year production incremental costs are estimated to range from between $257 and $467 to meet the new standards.

An innovative Power Line Carrier (PLC) Communication system for video and digitally signal processed data distribution using the existing DC copper wire is presented. The major contribution consists of a new signal coupler that achieves a stable transmission bandwidth on the DC electrical lines. Several weeks of continuous beta tests achieved video transmission on the trucks +12V wiring (from the back of the truck to the driver's cabinet) and product manufacturing and delivery has started. Benefits include: simplicity of application; ease of implementation; effectiveness with video and data; applicability to all application types; elimination of coax and twisted pair wiring and its maintenance.

It is the intent of this technical paper to inform tapered roller bearing producers and manufacturers of axle nuts about the results of recent research dealing with wheel bearing preload axial pressures. A testing program was conceived and perfected in the interest of correlating internal tapered roller bearing axial load pressures with the clamping forces introduced by tightening axle nut systems. Using the information presented in this technical paper, it will be possible for all manufacturers of wheel end components to develop appropriate installation instructions for their proprietary products. These instructions would be suitable for original OEM assemblies or during retrofit operations.

All friction materials swell. That is, they temporarily increase in thickness with an increase in temperature. Brake block swell is usually greatest the first time the brake heats them above 150°C (about 300°F). Block growth also involves a change of thickness from heating. But growth is permanent. It is determined by measurements taken at ambient temperature, before and after the block is heated. This paper introduces and defines several types of truck brake block thermal instability, and describes their effects on brake performance. Methods to measure thermal instability of brake blocks are described. Data are presented for several original equipment manufacturer (OEM) and aftermarket brake blocks. Information is given on the ways truck brake block thermal instabilities may affect brake performance and durability. Through better awareness and understanding of these thermal effects, better brake performance can be achieved with OEM and replacement brake blocks.

Four years have passed since the automated mechanical transmission was first introduced in city buses, and this system is now making steady inroads into the market. The development of this system was a result of the cooperation between Kinki Nippon Railway Co., Ltd., the largest bus and coach transportation company, and Hino Motors Ltd., the largest truck and bus manufacturer in Japan. First an investigation was conducted of the topography and traffic conditions of the bus routes, then trial runs and refinement of the computer control software was carried out using three chosen routes, and finally the actual performance of the system was tested according to the finalized specifications. This paper introduces the development process, provides a background to the city bus service, and describes the benefits brought by this system and the successful results of this cooperation.

The Pennsylvania Transportation Institute (PTI) operates the Bus Testing and Research Center for the Federal Transit Administration (FTA). The objective of this paper is to present a summary of important findings during the first eight years of Center operation. This paper presents an overview of the test procedures and a descriptive matrix of vehicles submitted for testing. A summary of test results is provided, which includes a distribution of failures classified by severity and subsystem type. The paper briefly describes the developmental status of including brake performance and emissions testing as well as future plans for the implementation of electric and hybrid-electric bus testing.

As competitive pressures in the automotive industry continue to increase the need for reduction in product development time, OEM's are searching for ways to eliminate non-valued added activities. Today, still too much time is devoted to the laborious process of manipulation of CAD geometry in the advanced stages of a program in order to develop feasibility for emerging design themes, involving the packaging and function of vehicle systems. Technology is being developed that will eliminate much of the tedium currently involved in this design engineering process. As theme iterations or packaging changes occur, CAD models that intelligently link the theme, the packaging, and the engineering “rules” will automatically “morph” into new designs. This Morphing process will execute CAD model changes according to engineering rules that are considered to be industry best practices.

The electrical system of a commercial vehicle is a critical component for reliable vehicle operation. While the demands on today's electrical system have increased dramatically due to higher horsepower engine environments and increased key-off loads, the design of these systems continues to evolve in order to meet these demands. Unfortunately, this design evolution has not kept pace with user expectations for enhanced performance, durability and reduced maintenance of the electrical system. In support of the TMC's S.1 Tomorrow's Truck initiative, this paper offers the following vision of future alternator requirements that will fulfill the expectations of commercial vehicle drivers, maintenance and support personnel. The intent of this vision is that it be used by designers and vehicle manufacturers as a guideline of desirable features for the alternators of tomorrow's truck.

Air conditioning is defined as the process of treating air so as to control simultaneously its temperature, humidity, cleanliness and distribution to meet the requirements of the conditioned space. As in the definition, the important actions involved in the operation of an air conditioning system are temperature and humidity control, air purification and movement. For these conditions this paper proposes a Automatic Climate Control(ACC) system of the bus. The system has cooling, heating, and dehumidifying modes, and is governed by dual 8-bit microprocessors. These modes are broken down into sub-modules dealing with control of the compressor, blower speed, damper position, air purifier, ventilators, preheater, air mixing damper and so on.

Fire apparatus are a particularly sensitive vehicle application when considering the management of the electrical power and power distribution system. Modern apparatus are equipped with a multitude of control systems critical to the mission of the apparatus, including engine controls, transmission, water pump, aerial hydraulics, lighting, warning, communications and instrumentation systems. The dependency of fire apparatus on these control systems, coupled with the large electrical loading of the emergency warning and lighting systems, require that a sound power distribution and energy management system be engineered into the vehicle electrical system.

Today's car manufacturers are integrating evermore complex multi-media equipment into their vehicles in order to meet the changes in consumers buying behavior. Examples of such equipment range from the car radio/cassette player, through audio CD Changer and mobile telephones through to sophisticated car navigation and video systems. In order to efficiently integrate all of these devices together and allow products from different manufacturers to inter-operate, a cost-effective evolutionary multimedia networking technology is required.

Air spring systems are increasingly used on suspensions for commercial vehicles. To prove their durability a reliable test procedure is necessary: to be applied already in the development stage to be used to qualify individual air spring manufacturers and to assure manufacturing quality. In this paper the test procedure, the test facility and some test results are presented. In the test facility the air spring is mounted on a fixture and is loaded by a servohydraulic actuator. The mounting of the air spring allows to simulate all operational deformations, being decisive for the durability. Based on the extensive measurements on proving ground and public roads the test program was worked out. The test program includes besides the loading and deformations during driving also kneeling operations as well as high and low temperatures. The accelerated laboratory tests deliver results which correspond to the existing experience at the service usage.

Engineering complex systems is challenged by problems of language, increasingly as systems become more complex. Prominent are (1) integration of subsystems using communication networks, and (2) integration of work of engineers, product planners, suppliers, and customers. Both “hard engineering” and “soft process” cases encounter some of the same language problems in different settings. This paper briefly notes aspects of the structure of language and meaning and how they relate to these system engineering contexts. A practical, model-based technique, the Protocol Information Model (PIM), is described, to integrate both “hard” engineered systems and “soft” work processes which use “shared communication channels”.

Several lead-free alloys have been studied for potential use in electronics by the National Center for Manufacturing Sciences(NCMS) Lead Free Solder Consortium that ended in 1996. Since then, one of these alloys has been studied using an existing product in order to determine the viability of Lead Free Vehicle Electronics. Design, supply chain, manufacturability, and reliability data for the electronics components and system are a part of this paper.