The director shall adopt and enforce rules as may be deemed necessary to accomplish the purpose of RCW 43.19.560
, * 43.41.130
, and * 43.41.140
. The rules, in addition to other matters, shall provide authority for any agency director or his or her delegate to approve the use on official state business of personally owned or commercially owned rental passenger motor vehicles. Before such an authorization is made, it must first be reasonably determined that state owned passenger vehicles or other suitable transportation is not available at the time or location required or that the use of such other transportation would not be conducive to the economical, efficient, and effective conduct of business.