* <a href="http://www.katu.com/news/Variable-speed-limit-signs-are-coming-to-Portland-136326623.html">http://www.katu.com/news/Variable-speed-limit-signs-are-coming-to-Portland-136326623.html</a> * <a href="http://www.docstoc.com/docs/53240095/Variable-Speed-Limits-Aim-to-Relieve-I-4-Congestion">http://www.docstoc.com/docs/53240095/Variable-Speed-Limits-Aim-to-Relieve-I-4-Congestion</a> * <a href="http://www.wsdot.wa.gov/smarterhighways/">http://www.wsdot.wa.gov/smarterhighways/</a> And there are lots of more links that shows how Traffic Relief was achieved in other countries such as the UK.