Toyota’s appropriately-named ‘Toyota Safety Sense’ accurately portrays the system functionality. The promotional material and the handbook correctly indicate the limitations of the system capabilities. System status information is clearly displayed in the driver’s direct line of sight by a head-up display. The bZ4X monitors that the driver keeps their hands on the steering wheel, and ‘locks-out’ the assistance system if there are repeated warnings. The car’s indirect driver monitoring system detects fatigue but not distraction. The system balances driver steering input with lane guidance, promoting co-operative driving.

The bZ4X combines map-based speed limit information with real time camera inputs to manage fixed, variable and temporary speed limit signs. The system also adapts for upcoming curves in the road but not for other road features such as junctions. The car responds to avoid or mitigate a collision in most of the test scenarios for automatic cruise control. The driver is supported through the S-Bend, staying within the lane at all but the highest test speed. The Toyota has a lane change assist feature. In the case of an unresponsive driver, the car performs a controlled stop within its lane. If the radar or camera is blocked, the bZ4X provides a timely warning and prevents system activation.

‘Toyota Safety Sense’, as fitted to the Toyota bZ4X, balances a high level of Vehicle Assistance with a similar level of Driver Engagement. Combined with excellent safety back-up, the system, overall, offers Very Good highway assistance.