What is the test for a jury to find a contractor responsible for causing a motor vehicle accident?

If the evidence supported an inference of the contractor's negligence in creating a condition dangerous to the public, the jury could have properly found a verdict against respondents. "A highway contractor doing work on a public highway or street owes to the traveling public the duty of protecting it from injury that may result from his negligence" (25 Cal.Jur.2d 99, quoted in Breslin v. Fredrickson, 1957, 152 Cal.App.2d 780, 786, 313 P.2d 597, 600) and is under [193 Cal.App.2d 305] 'a duty to protect the public against dangerous conditions existing where the public in rightful use of the roadway might enconuter such conditions.' Breslin v. Fredrickson, supra, 152 Cal.App.2d 780, 786, 313 P.2d 597, 600.