When traveling on expressways, what is the minimum speed limit that vehicles should not operate below?

The minimum speed limit on expressways is established to ensure the smooth flow of traffic and to enhance safety for all road users. When vehicles operate below the posted minimum speed limit, they can create hazards for faster-moving traffic, leading to potential collisions or disruptions.

Choosing the option that indicates vehicles should not operate below the posted minimum speed limit emphasizes compliance with traffic regulations that are designed to maintain an efficient traffic flow. It acknowledges that these limits are set based on various factors, including road design and safety considerations.

Other options offer specific figures, but they don't align with the fundamental principle that drivers need to respect the legally set limits. By acknowledging the importance of following the posted minimum speed limit, which varies by location, the correct choice ensures drivers contribute to overall road safety and operational efficiency.