What is the maximum speed for heavy trucks on open highways during daylight?

Answer: C — 60 mph

The correct answer indicates that the maximum speed for heavy trucks on open highways during daylight is 60 mph. This speed limit is designed to promote safety and reduce the risk of accidents involving larger vehicles, which often take longer to stop and require more distance to maneuver. Heavy trucks have different handling characteristics compared to passenger vehicles, and limiting their speed helps mitigate the potential for collisions, especially in areas where traffic volume might increase or where road conditions may change. Setting a maximum speed for heavy trucks also helps to create a more consistent flow of traffic. On open highways, where conditions are generally favorable for higher speeds, a limit of 60 mph allows trucks to maintain efficiency without significantly impeding the movement of other vehicles. It strikes a balance between operational efficiency for truck drivers and safety for all road users. Other speeds listed may be variances for different types of vehicles or specific road conditions; however, the designated maximum for heavy trucks ensures that the unique challenges they face on the road are adequately addressed.