Seattle’s chief road engineer Dongho Chang, next to Broadway’s new protected bike lane. Photo via the Green Lane Project on Facebook.

When activists painted a guerrilla bike lane in Seattle, they didn’t expect a traffic engineer to thank them. But that’s what Seattle traffic engineer Dongho Chang did, commending for bringing attention to the safety issue — and then installing a more permanent treatment soon after. Chang spoke with the National Complete Streets Coalition about a few of the Seattle Department of Transportation’s signature projects, the inspiration for his work, and what he’s learned in 25 years of traffic engineering.