The summer riding season (April – September) typically sees an increase in the number of people injured on motorcycles over 500cc, with more than two-thirds of those killed or seriously injured on the roads of Sussex having their collisions over the summer months.
While those injured commuting will always be a concern, these collisions typically take place in the same locations that non-riders have collisions while commuting. In order to try and reduce the number of motorcycle rider casualties in the summer months, we need to try and engage with leisure riders. As well as attending events popular with this community, we also plan activities along risk routes.
Looking solely at the location of collisions when looking for risk routes, gives a skew towards urban areas that are more commonly used by commuters, rather than the roads on which leisure rides typically take place.
These maps look at the number of riders having collisions in 1km x 1km grid squares in the summer months, compared to winter months. This takes the focus away from urban areas, and highlights routes which are more likely to see collisions in the summer months.
The attached maps show areas with higher numbers of motorcycle over 500cc riders having collisions in summer in red (with darker red meaning a bigger difference between summer and winter) and areas with higher numbers having winter collisions in green.
The first map, showing the south central area of Sussex shows how summer collisions are more prevalent on routes covering rural A roads, and in a few cases, B roads. The urban corridor along the coast has the higher prevalence of winter collisions.
The second map zooms in around the Brighton and Hove area. This also shows a prevalence of summer collisions on the A23 entering/exiting the city, as well as on the coast. This may suggest Brighton and Hove seafront as a popular final destination for motorcyclists travelling around Sussex on leisure rides.
The third and final map looks at average distance from home for those having collisions, keeping the focus on the Brighton and Hove area. We could expect the rural areas to remain red (further from home) and the urban areas green (within 5km of home), as by nature, fewer people live in rural areas. What is most interesting is that the A23 into the city is a dark red, representing people who were more than 25km from home, further supporting the idea that this route is popular with leisure riders and not just people commuting into the city from nearby towns.
Creating the maps
These maps were created in MapInfo 11.5 - we are awaiting an upgrade to 64 bit systems in order to be able to upgrade and take advantage of the many new features.
The 1km x 1km grid cells were created within MapInfo using the Grid Maker tool, and then cut to the area of Sussex using OS Boundary-Line data.
The collision data came from STATS19. Collision and driver data was linked, with the easting and northing columns from the collision table added to the driver table in order to be able to plot driver locations. The driver data was then queried in order to separate out those riding motorcycles over 500cc for the last five years. Three versions of the table were created – one table for all riders was saved before being further queried to get separate summer and winter tables.
Additionally, the map showing distance from home linked the postcodes of these drivers to Code-Point Open data, with the distance between the two sets of grid references then calculated.
For each grid square, the number of summer and winter collisions were counted, and average distance from home of the riders calculated. A query was then used to add an extra column calculating the difference in the number of summer and winter collisions.
Thematic maps were then created in order to colour each grid square – these were made semi-transparent so that the underlying map can still be seen, allowing us to see which roads each grid square covers. As we were mainly interested in the summer collisions, in the maps showing difference between summer and winter, all grid squares with more winter collisions were coloured green, while increments of 1 were used to show areas with more riders having summer collisions. For the map showing distance from home, those within 5km from home were coloured green, as this is the distance that around half of all drivers have their collisions within. 5km increments were then used for those further away.