I De Vlieger

On board emission and fuel consumption measurement campaign on petrol-driven passenger cars

Abstract Realistic emission and fuel consumption rates of petrol-driven cars were determined by on-the-road experiments in 1995. A validated, in-house developed, on-board measuring system was used. Six three-way catalyst (TWC) cars and one carburetted non-catalyst car were measured. The effects of road type, driving behaviour and cold start on CO, HC and NO x emissions and fuel consumption were analysed. In real traffic situations, emissions for TWC cars were found to be at least 70% lower than for the non-catalyst car. For TWC cars, emissions decreased across the board from city to rural and motorway traffic. Without a catalyst, motorway traffic resulted in the highest NO x emissions. Compared to normal driving, aggressive driving gave emissions which were up to four times higher. Except for NO x , calm driving resulted in lower emissions still. Comparable fuel consumption rates were obtained from normal and calm driving. Those from aggressive driving were higher, by as much as 40% in city traffic. Cold starts resulted in significantly higher CO and HC emission values than hot starts. These differences were less pronounced for NO x . Emissions from TWC cars were higher than generally expected, compared to the European emission limit values (91/441/EEC) and the emission factors used in Flanders and the Netherlands (Klein,1993) for the national emission inventories. Low-emitting cars during the emission test on a chassis dynamometer, as prescribed by the 91/441/EEC directive, did not necessarily give low emissions in real traffic situations.

Effects of traffic signal coordination on noise and air pollutant emissions

Traffic management solutions are increasingly called for to address problems of transport and mobility. In particular, coordinated traffic lights that create green waves along major arterials are an increasingly used strategy to reduce travel times. Although it is usually assumed that an improved traffic flow will result in lower vehicle emissions, little scientific research has been spent on the effects of synchronized traffic lights on emissions. Moreover, because changes in traffic flow do not necessarily influence travel times, noise and air quality in the same way, there is a clear need for a combined approach. This paper reports on a computational study in which a microscopic traffic simulation model (Paramics) is combined with submodels for the emission of noise (Imagine) and air pollutants (VERSIT+). Through the simulation of a range of scenarios, the model is used to investigate the influence of traffic intensity, signal coordination schemes and signal parameters on the noise, carbon dioxide, nitrogen oxides and particulate matter emissions along an arterial road equiped with a series of traffic lights. It was found that the introduction of a green wave could potentially lower the emissions of the considered air pollutants by 10%-40% in the most favorable conditions, depending on traffic flow and signal timing settings. Sound pressure levels were found to decrease by up to 1?dB(A) near the traffic signals, but to increase by up to 1.5?dB(A) in between intersections. Traffic intensity and green split were found to have the largest influence on emissions, while the cycle time did not have a significant influence on emissions.

Influence of gear-changing behaviour on fuel use and vehicular exhaust emissions

This study explores the influence of gear changing behaviour on vehicular exhaust emissions and fuel consumption using real drive cycles as an input. 235 different drive cycles, recorded from people participating in a survey, were imported in an emission simulation tool called VeTESS (Vehicle Transient Emissions Simulation Software). Emissions and fuel consumption were calculated with VeTESS using two different gear change assumptions (normal and aggressive). This paper reports on the differences in vehicle exhaust emissions between trips made with those two different settings.

Policy options for transport to reduce CO2 and tropospheric ozone

The Sustainable Mobility project, a national program conducted in Belgium in 1991-2001, focussed on the possibilities to reduce carbon dioxide and tripospheric ozone. Discussed are the twelve policy options within transport that were selected and evaluated on their effectivity to reduce emissions, and for their techno-economic and social feasibility. This paper considers assumptions being made and final results of the above project.

Emissions Of Mopeds And Motorcycles In Belgium

In this paper we report our estimates for the total emission of CO, NOX,VOC and COZ of mopeds and motorcycles in Belgium and indicate confidence intervals. Data on the fleet of motorcycles are readily available from registration records, but the number of mopeds had to be estimated. Different sources were evaluated to obtain a best estimate for the yearly mileage and a distribution over rural, urban and highway roads. Most emission factors used were provided by MEET. Emission factors for CO and VOC are much higher than the factors of modem petrol cars, When compared to the total Flemish road transport emission ( 1999) it turns out that mopeds and motorcycles can no longer be neglected. They are responsible for 11% (58ktonne; 7-15%) of the CO emission and 25% (22ktonne; 15-35%) of the VOC emission, These shares have doubled over the last decade. This can be explained by their success, but also by the introduction of environmentally friendly cars since the beginning of the nineties and the fact that more stringent emission regulations for mopeds and motorcycles came into force in 1997. When compared to the total emission of Flanders in 1999, the mopeds and motorcycles are responsible for 6,6°A of the total emission of CO and 6.9°/0 of the total emission of NMVOC, or, weighted to the capacity to produce ozone, of 3.7~0 in the total emission of ozone precursors. An attempt to quantify the noise emission by mopeds and motorcycles failed due to a lack of data.

AIR POLLUTION IMPACTS OF INLAND SHIPPING: TWO CASE STUDIES

Over the last years, a myriad of road transportation problems have been subjected to an analysis of emissions and environmental external costs. Other modes of transportation have been studied with much less diligence despite overt interest of policy makers. In this paper we present the results of two case-studies from Belgium where inland shipping and road transport were compared. The first case looked at the short distance transport of municipal solid waste from an intermodal transshipment area south of the city of Antwexp to plants north of the city. Two transportation scenarios were evaluated: by inland shipping over the river Scheldt and through the basins of the port, or by truck on the cities major roads and highways. The second case looked at long distance transport of large single items (>60 tonnes) from the cities of Tournai and Likge to Antwerp. Inland shipping trajectories were compared to road transportation. It was found that emissions and impacts from the inland shipping scenarios are not always lower when compared to all-road haulage with modem trucks. This is explained by the fact that European legislation has succeeded in lowering emission standards of trucks systematically over the last decade. The poor performance of inland ships is mainly due to high emissions of PM but is also deteriorated by the need for extra transhipment and terminal road haulage. Emissions from inland ships are rather poorly known and there is an urgent need for real-life measurements and the further drafting of emission standards for inland ships and fuels. Nevertheless, inland ships clearly have lower fuel consumption and carbon dioxide (CO2) emissions per tonne kilometre than trucks.

Influence Of Traffic ConditionsOn Fuel Consumption And Emissions -Brussels As A Case Study

In 1996 on-board measurements were performed on six passenger cars. These tests were executed in the centre of Brussels under various traffic conditions. All vehicles were measured for both fuel consumption and COi emissions. Two were also measured for CO, HC and NO% emissions. The chief emphasis was put on driving in the rush hour and smooth-flowing (on Sundays) traffic. The principal aim was to obtain realistic fuel consumption and exhaust emission values for Brussels. Secondly, to gain an insight into the relationship between consumption and emissions on the one hand and the process of traffic on the other. Furthermore, the measurement results have been used to upgrade an existing microscope traffic model with a fuel consumption module. In the process of designing an intersections and traffic control measures, energy and environmental aspects have to be taken into account if a more sustainable mobility is to be obtained.