Conference Paper

Influence of Gear Changing Behaviour on Fuel-Use and Vehicular Exhaust Emissions

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... This paper describes the experimental set-up and preliminary results of an ongoing survey with a duration of one year, using an on-board vehicle device for the collection of data regarding driving behavior. The survey's results on driving behavior will provide insight into the long term effects of training on fuel efficient driving and will eventually contribute to better methods for emission estimation [16]. ...
Conference Paper
Full-text available
This paper describes the methodology, hands-on experiences and preliminary results of a long-term survey on driving behaviour. During several months, the driving behaviour of 28 respondents was monitored. The methodology consists of using an on-board vehicle device and a web-application. The on-board device is equipped with a GPRS-modem, a WiFi connection (optional), a GPS system and a CAN-interface. Driving behavior is studied by logging GPS data on position and speed, together with various CAN-parameters (e.g. revs per minute, chosen gear etc.). Data is transmitted to a central server through the GPRS-network. The gathered information is used to assess the long term effect of an eco-driving course by analyzing the change in driving behaviour and monitoring fuel consumption, and using these inputs to simulate the emissions before and after such training. For 8 drivers that have taken an eco-driving course, weekly averages in fuel consumption were compared for several weeks ‘before’ and ‘after’ the course. For 7 of the 8 drivers, fuel consumption diminished (as was expected) in the range of 2.0 to 10.3 %. For one driver, fuel consumption actually increased slightly (0.85%) when measured over a period of 12 weeks. The best performing drivers were able to lower their fuel consumption week by week, showing that they actively practiced the new driving techniques and gradually get more familiar with them. These results suggest that even a 4-hour course on fuel efficient driving techniques can have a long-term and possibly permanent effect on fuel consumption, given that the driver is motivated. The decrease in fuel consumption can be reasonably linked to changes in gear-changing behavior, an increase in distance letting the car roll in gear, a smaller percentage of fast accelerations and a smaller percentage of large RPA-values (Relative Positive Acceleration).
... gentle, aggressive,…) will be used in a sensitivity analysis. In cases where the speed limit is very close to the point where most people shift e.g. between second and third gear, this may have a significant effect on the emissions (Beckx et al, 2006b). ...
Article
Full-text available
Speed reduction measures have become an increasingly popular way to increase traffic safety especially in urban areas. Recently many cities have converted entire districts into 30 km/h zones. In many European countries the maximum speed of haulage trucks is under discussion or review sometimes in combination with a ban on overtaking. Reducing the maximum speed is perceived and promoted by policy makers as beneficial to the environment because of reduced fuel consumption and lower emissions. These claims however have not been scientifically validated. They stem from the popular believe that the widely used Copert-approach, which is scientifically valid for average trip speeds, can be used to assess the environmental impact of speed management policies at a local scale. It is obvious that speed reductions in urban areas or on highways may have very different effects on PM emissions. On the other hand the simplistic idea that speed reductions increase urban emissions and decrease emissions on highways is probably wrong. Although few experts would make this assumption explicitly, it is very frequently made implicitly by the way that traffic and emission models are integrated. Integrating macroscopic traffic models with emission functions based on average speed only is clearly unsatisfactory. In addition, the lack of such functions for the PM emissions of petrol fuelled cars is an important problem even with advanced models such as VeTESS. In this paper we study the problem of accurately estimating the effects of speed managements policies on exhaust emissions of PM. Emissions for specific types of vehicles were calculated with the microscopic VeTESS-tool using real-life driving cycles and compared with results obtained using Copert-like methodologies. Our results indicate that emissions of most pollutants should not be expected to rise or fall dramatically. Nevertheless the conclusion for emissions of PM could be different. The effects of specific speed reduction schemes on PM emissions from trucks are ambiguous, but VeTESS results indicate that the PM exhaust from diesel passenger cars shows a significant decrease in urban areas onverted to 30 km/h zones. Exposure of residents to one of the most toxic components of the urban air pollution mixture may therefore also decrease. Unfortunately linking microscopic emission and traffic models raises other concerns such as a lack of validation of the most prominent parameters: acceleration and gear change behaviour.
... shopping or recreational activities ( Beckx et al., 2006). To study potential impacts on driving behaviour, a teaching course on economical driving after six months. ...
... This paper describes the preliminary results of an ongoing survey with a duration of one year, using an on-board vehicle device for the collection of data regarding driving behaviour. The survey's results on driving behaviour will provide insight into the long-term effects of training on fuel efficient driving and will eventually contribute to better methods for emission estimation [16]. ...
Conference Paper
This paper describes the measured long-term effects on fuel consumption of ecodriving education. The results are part of the long-term survey within the Flemish research program \“An activity-based approach for surveying and modelling travel behaviour”. During several months, the travel and driving behaviour of 28 respondents was monitored. The methodology consists of using an on-board vehicle device and a web-application. The on-board device is equipped with a GPRS-modem, a WiFi connection, a GPS system and a CANinterface. The GPS system allows the monitoring of travel behaviour. Driving behaviour is studied by logging various CAN-parameters (e.g. revs per minute, chosen gear etc). Data is transmitted to a central server through the GPRSnetwork. Alternatively, data can be transmitted using a WiFi connection when present. Respondents can access the data on a web-application and provide additional information. The gathered information is used on the one hand to develop a regional activity-based travel model (not discussed in this paper). On the other hand, the data is used to assess the long-term effect of an eco-driving course by analyzing the change in driving behaviour and monitoring fuel consumption, and using these inputs to simulate the emissions before and after such training. The data might also be used as feedback to the driver, to visualize his driving behaviour, and to help him understand what he can do to further improve his driving style. This paper discusses the long-term effect of an ecodriving course on fuel economy and driving style for eight participants. Keywords: on-board logging device, eco-driving, fuel consumption, driving behaviour, driving style, CAN.
... gentle, aggressive,…) will be used in a sensitivity analysis. In cases where the speed limit is very close to the point where most people shift e.g. between second and third gear, this may have a significant effect on the emissions (Beckx et al, 2006b). ...
Article
Full-text available
Speed reduction measures have become an increasingly popular way to increase traffic safety especially in urban areas. Recently many cities have converted entire districts into 30 km/h zones. In many European countries the maximum speed of haulage trucks is under discussion or review sometimes in combination with a ban on overtaking. Reducing the maximum speed is perceived and promoted by policy makers as beneficial to the environment because of reduced fuel consumption and lower emissions. These claims however have not been scientifically validated. They stem from the popular believe that the widely used Copert-approach, which is scientifically valid for average trip speeds, can be used to assess the environmental impact of speed management policies at a local scale. It is obvious that speed reductions in urban areas or on highways may have very different effects on PM emissions. On the other hand the simplistic idea that speed reductions increase urban emissions and decrease emissions on highways is probably wrong. Although few experts would make this assumption explicitly, it is very frequently made implicitly by the way that traffic and emission models are integrated. Integrating macroscopic traffic models with emission functions based on average speed only is clearly unsatisfactory. In addition, the lack of such functions for the PM emissions of petrol fuelled cars is an important problem even with advanced models such as VeTESS. In this paper we study the problem of accurately estimating the effects of speed managements policies on exhaust emissions of PM. Emissions for specific types of vehicles were calculated with the microscopic VeTESS-tool using real-life driving cycles and compared with results obtained using Copert-like methodologies. Our results indicate that emissions of most pollutants should not be expected to rise or fall dramatically. Nevertheless the conclusion for emissions of PM could be different. The effects of specific speed reduction schemes on PM emissions from trucks are ambiguous, but VeTESS results indicate that the PM exhaust from diesel passenger cars shows a significant decrease in urban areas converted to 30 km/h zones. Exposure of residents to one of the most toxic components of the urban air pollution mixture may therefore also decrease.
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The increasing use of road vehicles has caused a number of transport and environmental issues throughout the world. To cope with them, traffic calming schemes are being increasingly implemented in built-up areas. An example of such schemes are Tempo-30 zones. The traffic calming measures applied as part of this scheme must be carefully planned in terms of location and design details in order to obtain the desired reduction in speed, traffic volume and exhaust emissions and, last but foremost, to increase the safety and facilitate the movement of vulnerable road users. The coexistence and combined effect of these measures and their design details must also be taken into account. The purpose of this study was to investigate whether the applied traffic calming measures had a considerable bearing on the reduction in speed to the desired level, as assumed in the traffic calming plan. Three street sections starting and ending with different intersection types were chosen to examine the synergy of the applied traffic calming measures. The numbers and speeds of vehicles were measured in three day-long continuous surveys. As it was expected, the amount of speed reduction depended on the hourly traffic volume on a one-way street and various other traffic engineering aspects. The obtained results may be used to modify the existing speed profile models and can guide traffic engineers in choosing the most effective traffic calming measures.
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One of the most common traffic management schemes used in Belgium today is the conversion of entire districts, streets or street sections into 30 km/h zones. This is usually done in residential areas where the previous speed limit was 50 km/h. These measures, aimed at increasing traffic safety, are usually seen or even promoted as beneficial to the environment because of reduced fuel consumption and emissions. These claims however are unsubstantiated and stem from the believe that speed reduction measures in urban areas have similar benefits as those on highways. In contrast to this popular believe, wide spread emission estimation methods using quadratic functions such as the Copert/MEET approach would lead us to believe that emissions may rise dramatically. To shed some light on the problem we have calculated emissions for specific types of modern cars with the VeTESS-tool using real-life urban driving cycles. A comparison was then made with artificially modified driving cycles limiting the top speed to 30 km/h where appropriate and elongating the cycle to preserve the original cycle distance. Results indicate that emissions of most classic pollutants should not be expected to rise or fall dramatically. Nevertheless VeTESS results indicate that some emissions such as PM exhaust from diesels may show a significant decrease, whereas MEET functions assume a moderate increase. Exposure of residents to one of the most toxic components of the urban air pollution mixture may therefore also decrease.
Article
Full-text available
One of the most common traffic management schemes used in Belgium today is the conversion of entire districts, streets or street sections into 30 km/h zones. This is usually done in residential areas where the previous speed limit was 50 km/h. These measures, aimed at increasing traffic safety, are usually seen or even promoted as beneficial to the environment because of reduced fuel consumption and emissions. These claims however are unsubstantiated and stem from the believe that speed reduction measures in urban areas have similar benefits as those on highways. In contrast to this popular believe, wide spread emission estimation methods using quadratic functions such as the Copert/MEET approach would lead us to believe that emissions may rise dramatically. To shed some light on the problem we have calculated emissions for specific types of modern cars with the VeTESS-tool using real-life urban driving cycles. A comparison was then made with artificially modified driving cycles limiting the top speed to 30 km/h where appropriate and elongating the cycle to preserve the original cycle distance. Results indicate that emissions of most classic pollutants should not be expected to rise or fall dramatically. Nevertheless VeTESS results indicate that some emissions such as PM exhaust from diesels may show a significant decrease, whereas MEET functions assume a moderate increase. Exposure of residents to one of the most toxic components of the urban air pollution mixture may therefore also decrease.
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This paper describes the development of a global positioning system, enhanced data collection tool for the assessment of vehicle exhaust emissions. This involves the collection of activity and travel data on a personal digital assistant with built-in global positioning system receiver. By converting the second-by-second global positioning system based travel data into emissions, estimates are made of the exhausts produced by individual vehicle trips. Differences in travel behaviour and vehicle emissions were examined by gender and trip purpose.
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Previous analysis of London's congestion charging scheme (CCS) has shown that changes in vehicle speed are an important factor in reducing vehicle emissions. Therefore, a detailed investigation of network average vehicle speed in both central and inner London has been undertaken using a combination of the non-parametric Wilcoxon sign ranks test and a method for calculating the cumulative difference between mean speeds pre- and post-CCS, or cumulative sum (CUSUM) analysis. Within the charging zone (CZ), the Wilcoxon test has shown that the difference in speed between pre- and post-CCS periods has increased on average by 2.1 km h−1 and that these changes are significant at the p=0.05 level. The CUSUM analysis has provided evidence of the timing of this change in mean speed in the CZ and this agrees well with the introduction of the CCS on the 17 February 2003. In combination, these results provide compelling evidence that the introduction of congestion charging has significantly increased vehicle speed in the CZ and by comparison with the results in inner London, that these changes are not part of a wider trend. To examine one impact of this change we used an instantaneous emissions model, the Vehicle Transient Emissions Simulation Software, to undertake a comparison between the change in vehicle emissions associated with changing driving characteristics, between pre- and post-charging periods, and those associated with a change in average speed. The analysis was limited to three vehicle types: a Euro II LGV, a Euro III diesel car and a Euro IV petrol car, but showed that driving characteristics in central London have a relatively small effect on emissions of NOX and CO2 compared with the average vehicle speed. However, for PM10 emissions from the Euro II LGV the opposite was found and for this vehicle the driving characteristics were more important than the average speed in estimating exhaust emissions. For this vehicle, emissions increased between pre- and post-CCS periods by 4%. For the Euro IV petrol car NOX emissions also increased by 6% between pre- and post-CCS periods. These findings will help to further understand the extent to which congestion charging reduces vehicle emissions in London.
Scientific report 2003. Energy, environment and materials. Responsible publisher: Dirk Fransaer
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VITO (2003) Scientific report 2003. Energy, environment and materials. Responsible publisher: Dirk Fransaer.