photo by BJustin, via Twitter

With the Expo Line opening April 28 and testing underway, this sign from Portland is an explicit reminder to cyclists: be careful crossing the tracks!

To submit a photo for the Art of Transit, post it to Metro’s Flickr group, email it to sourcemetro@gmail.com or Tweet it to @metrolosangeles with an #artoftransit hashtag. Many of the photos we’ve featured can be seen in these galleries on Flickr.