Report numberRA-MOW-2008-008
TitleBlack points for noise annoyance by surface traffic in Flanders
SubtitleUncovering conflicts between quality of life of inhabitants and mobility
AuthorsDick Botteldooren
Luc Dekoninck
Dominique Gillis
Published byPolicy Research Centre for Mobility and Public Works, track Traffic Safety 2007-2011
Number of pages63
Document languageDutch
Work packageOther: Sustainable transportation

Sustainable surface traffic should guarantee the quality of life of the population living in the neighbourhood of traffic infrastructure while satisfying mobility needs. Conflicts between these goals are inevitable, not in the least because of historically grown constraints. Infrastructure was not always foreseen to carry the traffic load it carries today. In this study, noise annoyance, one of the most important components of poor quality of life was examined in the typical Flemish context. The main goals of this research were: (1) to identify outlier situations that merit detailed case studies that will aim at optimally joining mobility and quality of life; (2) to derive initial broad policy guidelines. 


In contrast to earlier work, this study starts from reported annoyance (SLO-0 and SLO-1) rather than from noise level mapping to identify subpopulations with high relative risk for noise annoyance. These subpopulations are distinguished using the spatial (density) and traffic characteristics (road categorization according to Streetnet) of the location. The main focus is on land use planning and traffic planning and not so much on technological factors that influence noise emission of the traffic such as road surface, vehicle fleet, etc.


The main findings of this work can be summarised as follows:

  • Being highly or extremely annoyed by road traffic noise makes people rate the quality of their general living environment as bad to very bad in a majority of cases. Thus the absence of noise annoyance is indeed a prerequisite for a qualitative living environment.
  • People living near roads of category 10 (highways), in dwellings lining streets of categories 20, 30 or 40, and in urban settlements cut by a major street, are significantly more annoyed by road traffic noise. About 30% of this population reports high to extremely high street traffic noise annoyance and this results in odds ratios for high noise annoyance close to 3. Thus focussing noise policy and case studies to these areas is very efficient. However, from all people in Flanders that are highly to extremely annoyed by street traffic noise only a very small minority (<1%) can be found near roads of category 10. This fraction increases to almost 10% for dwellings lining major roads and almost 20% for inhabitants of villages and cities cut by a major road. Hence, on a macroscopic scale, noise action plans focussing on this population will be more visible provided that they affect this whole population. The proximity of a road of category 20, 30 or 40 increases annoyance more than expected on the basis of exposure measured by Lden.
  • Traffic intensity allows concentrating the population with high road traffic noise annoyance living close to non-highway roads even further. For traffic intensities surpassing approximately 500 equivalent vehicles per hour during evening rush hour, the percentage of highly annoyed rises to 37%. In addition, for the same noise exposure (Lden) the effect (high annoyance) is lower than expected when traffic intensity stays below approximately 500 equivalent vehicles per hour. Hence adding traffic intensity to noise maps allows identifying hot spots for noise annoyance more sharply. Modelled mean traffic speed is related to traffic intensity and noise annoyance in a complicated way, which is not completely unexpected since the average speed represents a mixture of velocities and accelerations of the vehicles in the stream.
  • The percentage of the population highly annoyed by road traffic noise annoyance seems to drop slightly within 200m of a crossing of roads of categories 20, 30 or 40. This indicates that the lower traffic speed (due to speed regulation or traffic dynamics) seems to dominate over the added noise caused by accelerating vehicles. About 2% of the highly annoyed are found near these crossings. As such major road crossings could be a special focus in future noise policy, but prior detailed analysis of this particular situation is required to avoid making the wrong changes and increasing noise annoyance.
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The Policy Research Centre for Traffic Safety carries out policy relevant scientific research under the authority of the Flemish Government. The Centre is the result of a

cooperation between Hasselt University, KU Leuven and VITO, the Flemish Institute for Technological Research.


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