The highway passenger-kilometers in the US is forecasted to decrease slightly from 4.2588 trillion in 2024 to 4.2276 trillion in 2028. This downward trend suggests a shrinking demand in highway transport, contrasting with 2023's approximately similar figures. Notably, the year-on-year variations depict a gradual decline, averaging a negative CAGR over the past five years, reflecting consistent decreases.

Future trends to watch include:

Technological advancements in vehicle efficiency.
Shifts towards alternative modes of transport, like electric vehicles or public transportation.
Potential infrastructural developments or policy changes influencing highway use.