Wednesday, 3 June 2009

Road traffic noise perception map - update

The traffic noise perception map has recently been updated to combine the three years data from 2006 - 2008. This should give more reliable results as the sample size is larger. The approach used was similar to that used in previous years. The data was taken from the results of the 2006, 2007 and 2008 Quality of Life survey in Bristol. The results from the noise question were coded such that a value of 100 was given to each response that road traffic was a “Serious Problem” and a value of 50 was given to a response where noise was considered a “Problem – but not serious”. This data was then summarised to average out the ratings for each postcode and then the postcodes were mapped using a GIS package. The values of the noise ratings then form a surface, similar to a map of terrain. The values reported from the survey are overlaid on a base map of the city.

The map is similar to the 2006 version in that it shows hotspots around the M5 in Avonmouth, the inner ring road and the M32 corridor. The Parson Street Gyratory and Brunel Way are highlighted and Bath Road also seems to be a problem.

It is interesting that the summary data seems to show that the proportion of people reporting road traffic noise as a problem fell significantly in 2008 from the 2006 and 2007 levels.

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