 If voters give their approval, it will cost the average homeowner more than $250 a year more in property taxes. In all, the plan is worth more than $1.5 billion over eight years. At Seattle City Hall, Jeff Podula, Northwest News Radio. The State Transportation Commission approved changes to the toll rates on the 520 Bridge today starting on August 15th. The changes will increase the tolls by an average of 10% for the entire week. There will also be fewer rate variations throughout the week, resulting in six different prices instead of eight.