Methods of assessing driver behavior include monitoring vehicle systems and driver monitoring systems to accommodate for a driver's slow reaction time, attention lapse and/or alertness. When it is determined that a driver is drowsy, for example, the response system may modify the operation of one or more vehicle systems. The systems that may be modified include: visual devices, audio devices, tactile devices, antilock brake systems, automatic brake prefill systems, brake assist systems, auto cruise control systems, electronic stability control systems, collision warning systems, lane keep assist systems, blind spot indicator systems, electronic pretensioning systems and climate control systems.