GIS data showing 15-minute isochrones for different modes of travel (Walking, Bicycle, Walk + Transit, Bike + Transit) from population weighted centroid of LSOAs. The data covers Birmimgham and a 10mile wide buffered zone around the city (taken from the original England-wide data set). Travel time isochrones have been calculated based on Weekday AM peak-time timetables. Bike + Transit assumes you can board the transit service with your bike and then use it at the other end of your journey. The travel time isochrones were produced with OpenTripPlanner and the OpenTripPlanner for R package. The travel times were calculated for each LSOA’s population weighted centroid. Some centroids were slightly moved to facilitate routing. For example, if the centroid is in the middle of a lake then routing would fail. To build the OpenTripPlanner graph the OpenStreetMap was used as the road network extracted by Geofabrik terrain data was extracted from OS Terrain 50. Each lsoa isochromes are available for preview and download separately, as well as a zip that contains all four layers, but this option does not have a functioning preview.