This is Barbur Boulevard, in the southwest quadrant of Portland, headed south. Note the bike lane. With its relatively fast traffic and infrequent intersections, Barbur Boulevard is more appropriate for a bike lane treatment than many other streets.
The Portland Triathlon route included part of Barbur Boulevard. These signs were posted on utility poles. The city truck in the background is posting the signs. It would have been more energy-efficient to post them by bicycle, and probably as fast too, what with the frequent stops!