Which of the following statements about Missouri's speed limits are true?

Interstate highways also have minimum speed limits. The maximum and minimum speed limits are for ideal driving conditions. However, you are required to always drive at a safe speed for the current driving conditions. You must slow down in poor weather, on slippery roads, in heavy traffic, or under any other hazardous road conditions. Under such poor road conditions, you may be considered to be driving too fast if you drive at the maximum speed limit. [Speed Limit Signs, Chapter 3 – Pavement Markings, Traffic Signs, Lights, and Signals, Missouri DOR Driver Guide; MO Rev Stat § 304.012]