Downloadable papers marked 'Beta-version' in the title heading are not to be quoted without permission.
Published papers can usually not be downloaded, due to copyright. Limited personal distribution is usually permitted though. Make contact for copies.
Time pressure and driving speed
Many studies have been made on stress in bus driving. In this project, the aim was to see if bus drivers tried to compensate for being late by driving faster. No such effect could be found, probably because the general traffic flow determined speed to a higher degree than the personal inclination of the driver.
Current state of the project
Finished. Although it did not lead to any safe conclusions, this line of inquiry has not been pursued. However, data is available from other projects for similar calculations. The main problem is to quantify time pressure, as it turns out to be a bit elusive. Still, the working environment problem of time pressure is important, as bus driving schedules seem to get ever tighter. It is possible that this area will be revived when an opportunity comes.
Paper
af Wåhlberg, A. E. (1997). Time pressure, age and driving speed among bus drivers: A pilot study. Unpublished manuscript. Download pdf-file
Acknowledgement: This project was funded by the Swedish Road Administration in 1997 (www.vv.se), through a scholarship.
Economic (fuel efficient) driving; effects of instantenous feedback on truck driver behavior (Reduce)
There are several different technological systems marketed with the expressed goal of saving fuel by giving feedback to the driver. The nowadays common vehicle computer that show instantenous and average fuel consumption is a primitive version of this. In collaboration with Skogforsk and Drivec (amongst others), the feedback device of the latter (DV4) was installed and tested in logging trucks over about six months time. This project also involved diverse other technical systems for the measurement of fuel consumption and geographical position, and the transferral of all data over the GSM net, something which has already been tested by Skogforsk in a previous project (Transmit). More information about the Reduce and Transmit projects can be found on Skogforsk's homepage. However, although this page can be found in English (http://www.skogforsk.se/en/), this does not include the projects mentioned here.
Current state of the project
This project was finished by the end of 2003. The goals were largely not met, due to technical difficulties. It is therefore still uncertain if the DV4 works as a feedback device for reducing fuel consumption, i.e. if the drivers actually use it and can interpret the information correctly. However, although the number of drivers involved became too small to determine behavior change with any certainty, a large amount of data was gathered, and this resulted in a paper on the DV4 variables, and how well they explain the variance in fuel consumption.
Papers
af Wåhlberg, A. E., & Göthe, J. (2007). Fuel wasting behaviors of truck drivers. In I. M. Pearle (Ed.) Industrial Psychology Research Trends, pp. 73-87. New York: Nova Science Publishers.
af Wåhlberg, A. E. (2007). Fuel-efficient driving research; an area in need of exploration. In I. M. Pearle (Ed.) Industrial Psychology Research Trends, pp. 5-8. New York: Nova Science Publishers.
Acknowledgement: This project was funded mainly by Vinnova.
Economic (fuel efficient) driving; effects of training and feedback on bus driver behavior
Background
In the 1990's, the interest in ways of making drivers drive more fuel-efficiently gathered momentum in Sweden, due to the strong environmental and economical incentives. The way a vehicle is driven (the individual driving behavior) is a strong factor in the final fuel consumption. This behavior is possible to alter, with resulting individual savings of up to 20 percent (depending on how wasteful the original driving style was). One way of influencing drivers in a desired direction is by way of training them in 'defensive driving', or some other technique. An alternative way of changing driver behavior could be continous, always available, feedback on driving style. However, it should be pointed out that there is precious little research concerning how best to influence behavior, how large the mean savings may be, and if the effect 'wears off' with longer time periods.
Depending on the target of the implementation, some slightly different kinds of feedback could be used. However, it would seem likely that fuel consumption, traffic safety and passenger comfort all depend on the same main source of variance, which is something which could be described like variation in driving (acceleration behavior). Therefore, even if one specific target is chosen, the other will probably benefit anyway.
This project studies the short- and longterm effects of training in Heavy Ecodriving (which is one specific type of training in economical driving) and direct feedback (by a technical device) on driving style as measured by acceleration patterns, fuel consumption and passenger reactions.
This project used the opportunity presented by the local Bus Company in Uppsala (http://www.gub.nu) who trained their drivers in economical driving during the spring of 2002 as part of their scheme of environmentally friendly transport. In a later phase of the project, a feedback device (Econen) was installed (May 2003) in 25 buses to encourage drivers to save fuel. This evaluation will run to approximately February 2004.
Development through the years
The project was launched in 2001, and data gathering was started in August. By the end of 2001, something like 4000 hours of driving had been logged from five buses, and there was also questionnaire data from 645 passengers, and fuelling data for a large part of the fleet. During spring 2002, about 300 bus drivers were trained in Heavy EcoDriving. Data on accelerations, fuel consumption and passenger responses were gathered in similar amounts to the earlier phase and compared with the data from before training.
As outcomes of the project, three papers have been written so far (se below). The first concerns itself with methodology and results in the general area of fuel efficient driving, the second present training data from the bus driver trained at GUB, and the third passenger responses to changes in driving style. A fourth paper is under development, concerning the effects of training on fuel consumption and celeration behavior. Also, two papers utilizing data from the project has been produced, see the section below concerning driver celeration behavior.
Current state of the project
The project was finished during the summer of 2004. The final report was written in Swedish, as a light version of the papers produced (see the page in Swedish).
Papers
af Wåhlberg, A. E. (2002). Att mäta effekter av utbildning i sparsam körning. Transportforum 2002.
af Wåhlberg, A. E. (2002). Fuel efficient driving training - state of the art and quantification of effects. Proceedings of Soric-02, E141. Download pdf-file Note that the copyright of this paper is held by the Center for Transport and Road Studies, University of Bahrain, Kingdom of Bahrain. Used by permission.
af Wåhlberg, A. E. (2006). Short-term effects of training in economical driving; passenger comfort and driver acceleration behavior. International Journal of Industrial Ergonomics, 36, 151-163.
af Wåhlberg, A. E. (2007). Long-term prediction of traffic accident record from bus driver celeration behavior. International Journal of Occupational Safety and Ergonomics, 13, 159-171.
af Wåhlberg, A. E., & Göthe, J. (2007). Fuel wasting behaviors of truck drivers. In I. M. Pearle (Ed.) Industrial Psychology Research Trends, pp. 73-87. New York: Nova Science Publishers. ISBN: 1-60021-825-3
af Wåhlberg, A. E. (2007). Fuel-efficient driving research; an area in need of exploration. In I. M. Pearle (Ed.) Industrial Psychology Research Trends, pp. 5-8. New York: Nova Science Publishers.
ISBN: 1-60021-825-3.
See also the section on celeration behavior; some of these papers partly concern EcoDriving.
Acknowledgements: This project is funded by the Swedish Road Administration (www.vv.se), grant AL90AB 2001:7758, and the Bus Company Gamla Uppsalabuss. The latter is also making the research possible by extensive cooperation regarding planning, physical arrangements and data. The municipality collective transport planning company Uppsalabuss supply some data.
The difference in accident risk between differently sized truck configurations
Given that there are many economic incentives to use larger trucks, the question of traffic safety effects of changes in the vehicle fleets are of prime importance. There is some research into the question of accident risk change with vehicle size, but this seem to the first meta-analysis of the available material.
af Wåhlberg, A. E. (2008). Meta-analysis of the difference in accident risk between long and short truck configurations. Journal of Risk Research, 11, 315-333.
Available from Skogforsk in Swedish: af Wåhlberg, A. E. (2007). Trafiksäkerhetseffekter av ökad storlek på lastbilar. Resultatrapport Nr 635 Skogforsk.
Acknowledgement: This project was funded by Skogforsk.
