In previous posts I've looked at numerous examples of timelines on the web. Although this is a familiar representation it is by no means the only way of visualising temporal data. An interesting project funded last year by the Department of Transport produced a series of Travel-Time maps of the UK.

"Using colours and contour lines they show how long it takes to travel between one particular place and every other place in the area, using public transport. They also show the areas from which no such journey is possible, because the services are not good enough."

This travel time data is overlaid as a heat map with hourly journey durations separated by colour. The resulting diagram bears a strong resemblance to a weather map. The isobars of the pressure map (the borders separating the heat areas) have been termed "isochrones" on the temporal map.

The map of London is incredibly useful for anyone looking to move out but still commute into the centre every day.