Wash. Admin. Code § 468-270-077
When tolling is in effect on the I-405 express toll lanes, the Good To Go!T toll rate schedule shall be a minimum toll rate of $1.00 and a maximum toll rate of $15.00. Good To Go!T Pass toll rates shall vary in amount by time of day and level of traffic congestion, and will automatically adjust within the established toll schedule using dynamic tolling to ensure average vehicle speeds in the lanes above 45 miles per hour at least 90 percent of the time during peak hours. In the event there is a disruption in the ability to set tolls dynamically, the department may, on a temporary basis, adjust toll rates by time of day and level of traffic congestion within the range set forth in this section.
The commission shall periodically review the Good To Go!T toll rate schedule against traffic performance of all lanes in the I-405 express toll lanes corridor, as outlined in RCW 47.56.880 to determine if the Good To Go!T toll rates are effectively maintaining travel time, speed, and reliability for all lanes. Based on this review, the commission shall adjust the toll rate schedule as needed.
The toll rate for a Pay By Mail transaction is equal to the Good To Go!T Pass toll rate plus $2.00.
Wash. Admin. Code § 468-270-077