How much slower is the average speed of trucks compared to the average speed of automobiles, as indicated in a 2007 study?

Answer: C — 2 to 5 mph

The average speed difference between trucks and automobiles indicated in the 2007 study highlights that trucks typically travel 2 to 5 mph slower than cars. This range encompasses the effects of various factors such as weight, size, and cargo load that inherently make trucks less agile and capable of higher speeds compared to passenger vehicles. Understanding this speed differential is crucial as it has implications for road safety, logistics planning, and traffic flow. Trucks, being larger and often carrying heavier loads, require more time to accelerate and decelerate, and their speed limits can also be regulated more strictly in many jurisdictions. Knowledge about their average speed enables drivers to anticipate how trucks affect overall traffic dynamics and fosters better sharing of the road between different types of vehicles.