As recently as 2006, almost no one in Seville got around by bicycle. The city's bike network was nearly non-existent. When the leaders of this city of 700,000 in Andalusia decided to make bicycling a viable transportation option, they didn't mess around -- they built an 80-kilometer bike network in just 18 months -- and that was just the beginning.

Not long after the initial bike network was set in motion, a poll revealed that 80 percent of city residents approved of bike lanes. Most of the new bike lanes are bi-directional and placed at sidewalk grade to keep drivers out. Today, Seville has an expansive bike network and is approaching 10 percent bicycle mode share.

As you can see in this Streetfilm, few people wear helmets, and lots of older residents are out biking. The temperature approach 100 degrees while I was there, and it didn't discourage people from biking, even men in suits. The relatively large share of women who bike -- 35 percent of all bike trips -- is another testament to the success of the bike network.

Seville's bike infrastructure isn't perfect. Some of the new bike lanes are too narrow for the number people riding on them. There's a movement afoot to widen these sections and expand the bike network to more neighborhoods, as Seville aims to double the rate of cycling by 2022.