Provides that there shall be a presumption that shared parental responsibility is in the best interests of children unless: (1) The parents have agreed to an alternate award of residential placement or decision-making authority to only one parent;

(2) The limitations of RCW 26.09.191 are dispositive of the child's residential schedule; or

(3) The court finds that shared parental responsibility would be detrimental due to the age or needs of the child or children.

Directs the administrative office of the courts, pursuant to funding provided specifically for this purpose, to commission a study to commence by September 1, 2006. The study shall survey a statistically relevant number of geographically diverse final parenting plans in Washington to determine the allocation of residential time as between parents, including an analysis of gender disparities between parents, and the impact of legal counsel on outcomes of parenting plan disputes. The study shall be completed and a report provided to the legislature, the governor, and to the public within two years of the effective date of this act.