Michigan Commercial Driver's License (CDL) Practice Exam

Which statement is true about causes of vehicle fires?

1. Poor fuel efficiency can contribute to fires

2. Flammable cargo requires licenses

3. Poor trailer ventilation can cause flammable cargo to catch fire

4. Excessive speed causes overheating

The correct answer is: Poor trailer ventilation can cause flammable cargo to catch fire

The statement about poor trailer ventilation being a cause of flammable cargo catching fire is accurate because inadequate airflow within trailers can lead to heat buildup, which may ignite flammable materials. When cargo that is susceptible to combustion is stored in a confined space with poor air circulation, and if temperatures rise due to external factors or heat generated by the cargo itself, there is an increased risk of fire. Ventilation is essential for maintaining a stable temperature and preventing the accumulation of heat, especially in trailers carrying products that can ignite easily. Conversely, factors like fuel efficiency, licensing for transporting flammable materials, and speeding are related to vehicle operation and safety but do not directly correlate with the ignition of fires in the same way that airflow and heat management within a trailer do. Thus, understanding the importance of proper ventilation can help prevent fire hazards in commercial transporting scenarios.