Does the design immunity defense apply to a motor vehicle accident?

In the second case, plaintiffs' decedent was killed after a head-on collision with another vehicle which had illegally crossed into her lane of travel. She tried to avoid the collision by swerving to the right but went over a steep embankment into a channel from which the embankment had been excavated. Her car overturned, and she drowned in the channel. (Levin v. State of California (1983) 146 Cal.App.3d 410, 194 Cal.Rptr. 223.) The court noted that the rationale of the design immunity defense is to prevent a jury from reweighing the factors considered by the governmental entity which decided [208 Cal.App.3d 868] to approve the design. However, the defense does not immunize decisions which have not been made. Here, there was no evidence that the public official had considered all aspects of the roadway design and weighed the alternatives before approving the plan. Accordingly, the state failed to establish that the roadway design had been approved by an authorized public official. (Id. at p. 418, 194 Cal.Rptr. 223.)