Final answer:
The least important factor when choosing driving speed on the interstate is the temperature of a refrigerator, which has no relevance to vehicle operation or road conditions.
Step-by-step explanation:
The least important thing to consider when selecting your speed on the interstate is the temperature of a refrigerator at any given time. This factor is unrelated to driving conditions and vehicle operation. When choosing your driving speed, the most important considerations should include the posted speed limit, the ideal speed for road conditions, and the instantaneous speed indicated by your car's speedometer. It's also essential to understand the distinction between the de jure speed limit posted on signs and the de facto speed limit, which is the threshold speed at which law enforcement may issue a traffic citation. When addressing the speed-choice model, factors such as road use and accident probabilities take precedence over unrelated metrics like refrigerator temperatures.