 Mayor Bruce Harrell signing the proposal this hour. The Washington State Transportation Commission is set to hold its final public hearing today on a proposal to change toll rates on the State Route 520 bridge. The proposed changes would increase tolls by an average of 10%. The new rates go into effect August 15th if the commission approves them at today's meeting, which is underway. The Seattle City Council has approved office to housing conversions, a move that could result in up to 2,000 new housing units in the city.