Timothy W. Martin wrote about the rise of GPS art runs:

• An increasing number of exercise enthusiasts are mapping out their trails with the aim of having their route create an image or phrase.
• You can get a sense of where the art was made by the GPS “brush-strokes”. American cities are usually laid out in a grid so the art tends to be blocky.
• Meanwhile European cities tend to have longer, more flowing lines.
• The image created by runners is usually very different from that created by bikers.
• Some then frame the print outs of their route and depict them at galleries.
• Running crazed couples have planned runs where the end result spells out a proposal.
• Casual runners say that it helps break up the monotony of running and encourages them to get out more.
• Things like cloudy weather, low batteries, and signal blocking skyscrapers can have the unfortunate effect of ruining a meticulously planned piece art run.

Read more here.

Source: The Wall Street Journal