Thursday, September 26, 2019

The Orientation of UK Runways

The orientation of airport runways are normally determined by prevailing wind directions. Aircraft find it easier to land without a crosswind and planes can more easily take-off and land upwind. Aircraft also need a lower ground speed at both landing and take-off when they are pointing into the wind. As a consequence runways are usually built to point in the prevailing wind direction. In fact compiling a wind rose showing local wind directions is often one of the first steps taken when building a new airport runway.

In the UK the wind blows more from the the west or south-west than from any other direction. These prevailing winds come from the the Atlantic Ocean. Because of this south-westerly prevailing wind direction we would expect more airport runways in the UK to run west-east (or southwest to northeast) than north-south.

You can explore the predominant UK runway orientations for yourself on my new Runway Orientation interactive map. This map plots all the runways in the UK using data from OpenStreetMap. The map also includes a dynamic compass rose. This compass rose plots the distribution of all runways in the current map view. If you zoom the map out to show the whole of the UK this compass rose shows the distribution of all runways in the UK by direction. Because the compass rose is dynamic if you zoom in on different areas of the UK the chart will update to show the distribution of runways currently shown on the map.

If you are interested in the orientation of airport runaways elsewhere around the world then you can refer to the beautiful Trails of Wind map. This interactive map colors airport runways around the world based on their orientation. Blue lines indicate runways on a north-south axis and yellow lines show runways on an east-west axis. If you zoom in on the central states in the USA you can clearly see a majority of runways have a north-south orientation. The UK, France and Germany seem dominated by east-west orientated runways, while around the Mediterranean runways appear to be constructed along a north-south axis.

My map was of course inspired by the brilliant Trails of Wind map. It was also heavily inspired by and built on Vladimir Agafonkin's fantastic Road Orientation Map. I simply hacked Vladimir's Road Orientation map to show the orientation/bearing of UK runways rather than global roads.

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