Sometimes the traffic on roads develops emergent properties, creating beautiful patterns you never realized were there.

Ho Chi Minh City, Vietnam, directed by Rob Whitworth, 2012

Rush Hour, by Black Sheep Films, 2014

Air traffic above Changi Airport, Singapore, directed by Milton Tan, 2014

Venice, Italy, directed by Jonathan Heuser, 2012

Midday traffic on State Route 163, San Diego, California, reorganized by color, directed by Cy Kuckenbacker, 2013

Landings at San Diego International Airport, San Diego, California, directed by Cy Kuckenbacker, 2012

Los Angeles, California, directed by Chris Pritchard, 2014

Bangkok, Thailand, directed by Oliver Wolfson, 2010

The 51-202 overpass near Phoenix, Arizona, by D Squared Productions, 2011

The air traffic above Changi Beach, Singapore, directed by Milton Tan, 2013

And what if we clean all people and vehicles from a city? Here is Barcelona, without any signs of life, by myLapse, 2014: