Bicycle advocates are reacting with horror to a rash of traffic accidents involving bikes and motor vehicles over the last five days.

Three bicyclists have died, and three more have been sent to the hospital.

Rob Sadowsky, who directs the Bicycle Transportation Alliance, says, "My first reaction is I'm horrified. It's just hard to take and hard to experience as someone who's a bicyclist to know that other people out there are struggling and getting hit. As the director of a bicycle advocacy organization, I start thinking what can we do, how can we get messages out to both drivers and byclists in terms of their behavior, in terms of their activity, so that they can be safer."

Wednesday night, three cyclists were hit near the Washington County city of North Plains. One died.

Thursday, authorities say a logging truck struck and killed a cyclist on Highway 101.

Over the weekend, an 18 year-old bike rider in Clackamas County was killed.  A separate incident left a Portland cyclist hospitalized.