Diesel prices have spiked to $5/gallon, elevating fuel to ~28% of trucking costs from a typical 20-25%. The speaker states this will "crimp margins and probably crimp demand." Higher fuel costs directly increase operating expenses for trucking and railroad companies. Fuel surcharge recovery lags (one week for trucking, 30-60 days for railroads), creating a temporary margin squeeze. Concurrently, sustained fuel inflation reduces consumer spending power, weakening freight demand. The transportation sector faces compressed margins and softening demand in the short to medium term, making it an unattractive area for investment (AVOID). A rapid decline in fuel prices would turn the surcharge lag into an earnings tailwind. Resolution of the Middle East conflict could also alleviate fuel price pressure.