In Armendariz v. Mohave County, 1 CA-CV 15-0571, 2017 WL 587089 (App. Feb. 14, 2017), the Arizona Court of Appeals held that Mohave County was entitled to legislative and administrative immunity for its decision to not install a traffic control device at an intersection with a private easement.  As part of a traffic control study along a rural stretch of road, the County relied on an informal policy of not signing private roads to exclude the intersection from its study.  The Court held that “[n]othing in the immunity statute [A.R.S. § 12-820.01] or appellate precedent supports [the] suggestion that the determinations protected by the immunity statute must be formally enacted decisions of a municipal body.”  Thus, a written policy or directive is not required to support an “administrative function involving the determination of a fundamental governmental policy.”

The Court also concluded that the County’s informal policy of not including intersections involving private easements in its traffic control studies, and adherence to that policy in this case, constituted an “actual decision” that protected it from liability for failing to install a traffic control device at the subject intersection.  This is the first time the Court has squarely addressed whether a particular decision constituted an affirmative (actual) decision or a decision by default and concluded it was an “actual” decision.