Which is NOT true about the National Highway System?

Answer: D — It carries 60% of tourist traffic

The National Highway System (NHS) is a vital network that includes the most significant roads in the United States, focusing on promoting efficient transportation of goods and people. The correct statement regarding what is not true about the NHS pertains to its role in carrying 60% of tourist traffic. While the NHS is indeed a major corridor for both personal and commercial travel, the specific statistic of carrying 60% of tourist traffic does not accurately reflect the comprehensive role of the NHS in relation to tourism. In reality, while major highways are certainly used by tourists, the percentage attributed to the NHS can vary and isn't as high as 60%. Various other roads, including state and local routes, also play significant roles in tourist traffic, especially in areas where attractions and accommodations are located. On the other hand, the other statements about the NHS being responsible for more than 44% of all vehicle traffic, carrying 75% of heavy truck traffic, and comprising 4.1% of the nation's roads are well-supported by data. These figures highlight the crucial importance of the NHS in the overall infrastructure, showcasing its extensive usage and significance for transport logistics across the country.