Productivity change in transport: a survey

Because of the importance of transport in promoting economic development, there has been a long‐standing interest in the performance of transport industries and in the conditions which are likely to promote productivity growth. Fundamental to any debate on the subject, though, is the need to advance a satisfactory account of production and a way of deciding when productive performance has changed. This paper points out that there are pitfalls in the common practice of using measures such as output per man‐hour as an indicator of productivity and argues that a thorough understanding of the relationships between inputs and outputs can proceed from a knowledge of the economic theory of production.

The paper describes the relevant theoretical concepts and then examines applications of that theory in transport industries. It transpires that there is a growing literature on the subject, demonstrating a worldwide and multimodal interest in developing more rigorous and satisfying ways of measuring and analysing productivity difference. The techniques employed range from the more complex models at the forefront of economic theory, to rudimentary methods which are, at best, capable of testing only the simplest types of hypotheses. Nevertheless, it is argued that these studies have achieved a remarkable degree of success in enhancing analysis.

There can be no doubt that techniques will undergo further developments. However, it is likely that the greatest successes will come about through improvements in data which will permit applications of more complex, but proven techniques of analysis in relatively neglected areas such as road and maritime transport.     

Introducing advanced electronic driver support systems: An exploration of market and technological uncertainties

R&D in the field of driver support systems is increasingly paid attention to. These systems can contribute significantly to public traffic goals. However, there is much uncertainty about future technology developments, market introduction, and impacts on driver and traffic behaviour. An international Delphi study collecting expert opinions on these issues is partly described here. The Delphi study was organized in three rounds. Opinions of 50 experts from the USA, Japan and Europe were collected. The paper is limited to market introduction, and technological and driver-behavioural barriers. The main conclusion is that future developments are less obvious than often assumed.     

Compulsory wearing of seat belts in the United Kingdom—the effect on patients and on fatalities

This is a two‐part study. The main part reports on all car occupant patients coming to the accident and emergency departments of 14 hospitals in the United Kingdom in the years immediately before and after the introduction of seat belt legislation. This included about 5% of such casualties in the country. Using the strict methodology of stating expected changes in the form of hypotheses prior to analysis, it was confirmed that a large number of improvements occurred. These included a reduction in the total number of patients, number of bed days, multiplicity of injuries, injuries to the brain and chest, and many facial injuries. It was confirmed that after legislation there was some increase in neck sprains and sternum fractures. Front‐seat passengers obtained much greater benefits than did drivers.

In a much smaller study in fatalities (again covering about 5% of fatalities in the country) it appeared that improvements occurred in head, chest, and abdomen injury, while limb injuries were not greatly changed and spinal injuries increased.     

Integrated fuzzy signal and ramp‐metering at a diamond interchange

We propose a fuzzy logic control for the integrated signal operation of a diamond interchange and its ramp meter, to improve traffic flows on surface streets and motorway. This fuzzy logic diamond interchange (FLDI) comprises of three modules: fuzzy phase timing (FPT) module that controls the green time extension of the current phase, phase logic selection (PLS) module that decides the next phase based on the pre‐defined phase sequence or phase logic and, fuzzy ramp‐metering (FRM) module that determines the cycle time of the ramp meter based on current traffic volumes and conditions of the surface streets and the motorways. The FLDI is implemented in Advanced Interactive Microscopic Simulator for Urban and Non‐Urban Network Version 6 (AIMSUN 6), and compared with the traffic actuated signal control. Simulation results show that the FLDI outperforms the traffic‐actuated models with lower system total travel time, average delay, and improvements in downstream average speed and average delay. Copyright © 2011 John Wiley & Sons, Ltd.     

Modal split models based on car availability: the application of such models in studies of medium sized towns

This paper discusses the need for a new approach to urban transportation modelling in recognition that at least in medium sized towns the choice of model is largely dominated by car availability.     

An inter‐Urban freight mode choice model

The Australian Railway Research and Development Organisation is conducting a study with one of its objectives being to determine factors affecting freight mode use. Part of this has included the development and calibration of freight mode choice models. This paper outlines the results obtained from the application of an Elimination‐by‐Aspects (EBA) model to this task. The paper describes the theoretical background to the EBA model, within the context of a general choice process, and then describes the results of the model when applied to three samples of shippers involved in regional freight transport.     

A model of managers’ preferences for location of freight facilities

The paper reviews the need for a better understanding of the factors which affect the location of freight facilities, such as depots, terminals, freight forwarding centres, distribution centres, etc. The development of an Elimination by Aspects (EBA) model to analyse such location decisions by the managers of freight firms is described. The results are shown to be comparable (perhaps even superior to) those obtained with a logit model. Conclusions are drawn with respect to both the use of the EBA model to analyse freight facility location preference, and the factors which affect such preference. Five factors were found to be significant: closeness to existing customers, closeness to arterial roads, availability of suitable sites, cost of truck fleet operation, and closeness to labor.     

Variation in the value of travel time savings and its impact on the benefits of managed lanes

This paper examines the variation in the value of travel time savings (VTTS) for travelers with a managed lane (ML) option when taking an ordinary trip versus a trip that is unusual in some way. VTTS estimates vary substantially depending on the urgency of the trip made. At the low end, the mean VTTS for a traveler who wants to make extra stops and still arrive on time is approximately 10% higher than that for an ordinary trip. At the high end, a traveler running late for an appointment shows a mean VTTS that is approximately 300% higher than that for an ordinary trip. These estimates vary widely over the population of travelers. In light of these variations, the value of an uncongested travel alternative (such as MLs) is examined and found to be greatly undervalued if using typical VTTS estimates.     

An assessment of the demand for new transport technology in Australia

This paper summarizes the constraints which a technological innovation in transport must satisfy if it is to achieve widespread application. The existing and likely future travel demands in Australia are reviewed, and for certain types of travel it is concluded that existing modes may become unsuitable or unacceptable. In these areas, it is possible that a new transport technology may find application. In all other areas, it is considered that existing modes, or their functional successors, will continue.

Five possible demand areas in which new transport technology may find application are identified. These are as follows:

1) High speed distribution systems may be introduced in Australian CBD's (Central Business Districts) within the next ten years. These may be progressively extended to provide radial public transport services to the CBD. It is also possible that these systems may eventually be extended to provide a dual‐mode capability in inner‐suburban areas as a partial alternative to freeway construction.

2) New town developments which may be introduced in Australia could include various forms of advanced transportation systems.

3) New aviation modes, possibly including short take off and landing aircraft operating from suburban airports may be introduced to cater for inter‐urban travel.

4) A demand‐responsive transport system to cater for the needs of the transport poor in urban areas may find limited application.

5) In the longer term, possibly by the turn of the century, an improved transport system capable of providing door‐to‐door service over the whole of an urban area and operating under a dual‐mode configuration appears to be possible. It probably would emerge from development of an incremental nature and eventually include the installation of a new technology in the then existing freeway and railway reservations in the city.     

The vehicle emissions and performance monitoring system: analysis of tailpipe emissions and vehicle performance

This paper describes tailpipe emission results generated by the Vehicle Performance and Emissions Monitoring system (VPEMS). VPEMS integrates on‐board emissions and vehicle/driver performance measurements with positioning and communications technologies, to transmit a coherent spatio‐temporally referenced dataset to a central base station in near real time. These results focus on relationships between tailpipe emissions of CO, CO₂, NO_x and speed and acceleration. Emissions produced by different driving modes are also presented. Results are generally as one would expect, showing variation between vehicle speed, vehicle acceleration and emissions. Data is based upon a test run in central London on urban streets with speeds not exceeding about 65 km/h. The results presented demonstrate the capabilities of the system. Various issues remain with regard to validation of the data and expansion of the system capability to obtain additional vehicle performance data.