Final answer:
Vehicle equipment failures include defects that lead to accidents, like faulty brake systems. External factors such as severe weather or improvements in car features like fuel efficiency, are not equipment failures. Human errors or operational issues are also distinct from vehicle equipment malfunctions.
Step-by-step explanation:
The vehicle equipment failures that may cause accidents include a wide range of defects, but not every situation poses the same risk. In Situation 3, a manufacturer is aware of defects in the brake system of one of their automobile models, which inevitably leads to brake failure and numerous accidents. The manufacturer is, therefore, liable for these failures and the resulting injuries and deaths.
This is a clear example of equipment failure leading to accidents. On the other hand, situational aspects like weather conditions, especially an exceptionally cold winter, are not examples of vehicle equipment failure that may cause accidents. Such environmental factors are external to the vehicle's systems and components.
In Example 4.17, the safety engineer's concern is about human error, specifically the failure of employees to follow instructions, which is an operational issue rather than a vehicle equipment failure. Likewise, in the situation with the woman transporting cupcakes, the mishap is a result of sudden braking leading to the cupcakes' destruction due to inertia, but it is not indicative of any vehicle equipment fault. Lastly, the improvement in fuel efficiency is a positive aspect of vehicle performance and is clearly not related to equipment failure.