I need to generate average drive time polygons for a number of driving test sites across England for accessibility assessment purposes and setting the conditions to a particular time frame and day of week if not ideal. I just need an average across either a 7 day week (which can be set) or for a particular month. Using a fixed time period (e.g. 15 minute period or hourly period) and fixed day is not ideal for analysis, since travel times vary across geography and temporally, so having an average is a little more useful when undertaking high level analysis.