Autonomous Vehicles Self$-$driving vehicles periodically suffer from a disengagement of the self$-$driving feature. In these cases, it is important to know how long it takes for the driver to manually take control of the vehicle. In a study of $487$ instances where a self$-$driving vehicle became disengaged from the self$-$driving feature, the mean time for the driver to take control was $0\mathrm{.}84$ second with a standard deviation of $0\mathrm{.}90$ second.