At last week's Bicycle Advisory Committee meeting, DDOT announced that they had a meeting planned with USPS on how to stop parking in bike lanes and cycletracks and that they were planning more outreach to UPS and FedEx on the issue.
USPS is a unique issue because their vehicles have no license plates and thus can't be ticketed. DDOT is goiing to try to educated them on the safety issues related to parking in the bike facilities.
UPS and FedEx can be ticketed, and are, but the companies have billing arrangements with the city and just treat it as a cost of doing business. It was suggested that they ask the companies where loading zones are needed if the current ones are inadequate. Outreach to BIDs could help with identifying better LZ placements.