Kohl v. City of Phoenix
In Kohl v. City of Phoenix, 215 Ariz. 291, 295, P 15, 160 P.3d 170, 174 (2007), the plaintiffs sued the City of Phoenix when their teenage son was killed in an auto accident at an intersection without a traffic signal. 215 Ariz. at 292, P 2, 160 P.3d at 171. The parents alleged the City's negligent failure to install a traffic signal at the intersection caused their son's death. Id.
The City countered that its decision not to install a signal at the intersection was entitled to absolute immunity under A.R.S. 12-820.01. Id. at P 3. The central issue in the case was whether the City's decision flowed inexorably from the policy-level decision to adopt a computer program to automatically identify dangerous intersections for signalization or, whether the City's decision was an operational failure because the City's staff relied not only on the computer program in question, but also on their engineering judgment. Id. at 296, P 22, 160 P.3d at 175.
The Court held that the City was entitled to absolute immunity. Id. at 298, P 31, 160 P.2d at 177. The court reasoned that the opportunity to use engineering judgment did not arise because the computer program limited the exercise of such judgment to the twenty most dangerous intersections, which excluded the intersection where the teenager was killed, because it was never ranked higher than seventy-first among locations surveyed. Id. at 293, 296, PP 7, 22, 160 P.2d at 172, 175.