Analysing deprivation in road safety analysis projects is useful for identifying whether certain groups of society are more at risk of being injured on the road. It can also help to build up a profile of who to aim for with your planned intervention.
As the Index of Multiple Deprivation is applied to areas of roughly equal population (LSOAs and Data Zones) it isn’t surprising that the population is almost equal across all deciles. For this reason there is little to be gained in using population to create rates and indices for analysis at national level. However, indexing by population can be beneficial when looking at individual authorities where the distribution of deprivation isn’t so even.The chart above shows pedestrian casualties from the highway authority of Surrey between 2010 and 2014. It shows that most casualties are from the least deprived decile with only 15% of casualties from the more deprived deciles.
There are a high number of casualties from the least deprived parts of Surrey but as the index value of 82 shows this is 18% lower than expected based on the population of the least deprived areas of Surrey. Although the number of casualties from the more deprived 30% decile is low (40), these communities are over-represented as casualties at more than twice the expected level based on their population within Surrey, as shown by an index value of 217.