Transitioning between operational modes of an autonomous vehicle

A system for transitioning a vehicle between a first operational mode and a second operational mode, the second operational mode having a greater degree of manual involvement than the first operational mode, the system comprising:

• one or more sensors located onboard the vehicle, the one or more sensors operable to sense at least a portion of an external environment of the vehicle, the one or more sensors being configured to capture one or more driving scenes along a travel route while the vehicle is operating in the first operational mode;
• a user interface element located within the vehicle, the user interface element being at least one of a display, a light source, a speaker, or a haptic actuator;
• and
• one or more processors operatively connected to the user interface element and to the one or more sensors, the one or more processors being programmed to initiate executable operations comprising:
• comparing the captured one or more driving scenes to a predetermined set of driving scenes;
• determining whether an operational mode transition event has occurred while the vehicle is operating in the first operational mode, the operational mode transition event being determined to have occurred at least when there is a sufficient mismatch between the captured one or more driving scenes and the predetermined set of driving scenes;
• responsive to determining that an operational mode transition event has occurred, determining a time buffer for continuing in the first operational mode before switching to the second operational mode;
• and
• presenting a transition alert within the vehicle using the user interface element, the transition alert corresponding to the determined time buffer.