The study of travel access looked at travel by walking, cycling and public transport.
Routes and distances were calculated using:
- Ordnance Survey's view of the road network – the 'Integrated Transport Network' (ITN)
- Basemap Ltd's view of urban paths
Routes were not considered for walking and cycling where it is not feasible to travel by these means – for example, along the M25.
For journeys where the starting point is not on the highway network, we measured the straight-line distance to the nearest highway, and then multiplied it by 1.2. This is because journeys are not likely to be an exact straight line.
Walking times were calculated using an average walk speed of 4.8 kilometres per hour, equal to 80 metres per minute. This is accepted as the speed at which people choose to walk in normal conditions. Many people can walk faster, but typically choose not to.
Cycling times were calculated using an average cycle speed of 16 kilometres per hour, equal to 10 miles per hour – a useful average speed when allowing for steep gradients, frequent signalled junctions or crossings, and vulnerable cyclists.
16 kilometres per hour has been used for the parts of the highway network where people can cycle. For areas such as alleyways and footpaths, where people should not cycle but may push their bike, a walking speed of 4.8 kilometres per hour has been used.
Cycling speeds vary depending on the fitness and experience of the individual, type of bike, loads carried, highway network, gradients and winds.
National Public Transport Data Repository (NPTDR) data was used for these calculations. This data uses bus, rail, coach and ferry timetables for one week in October 2015.
Public transport journey times are taken from the timetables, with 5 minutes allowed for changing between services. This is added in the middle of the journey before boarding the next service, not at the end.