The simple answer is not very often.  Under normal circumstances, the only time you can legally travel at speeds above the posted limit is when you are passing on a two lane road (one lane each direction).

Under 46.61.425, you can go above the speed limit while passing a vehicle which is traveling at under the legal limit.  This can be done only for a distance necessary to complete a pass with a reasonable margin of safety and also is subject to RCW 46.61.120 – which describes the limitations of passing on the left.

In general, however, Washington’s speed limits are hard limits.  They cannot be exceeded.  If you drive higher than the posted limit, it is technically a violation.  Our Washington speeding attorneys fight hundreds of tickets in WA State every year.  If you or someone you know has been issued a speeding ticket here in Washington, we invite you to call our offices to learn more about how we can help.