Warren Buffett has often said he’d look at rail car loadings if he were forced to pick just one economic statistic to be stuck with for the rest of his life. The figure, he says, is a great real-time proxy for the health of the economy.

Consider that when looking at the latest regulatory filing from Buffett’s Berkshire Hathaway. The firm’s railroad, Burlington Northern Santa Fe, had a 23% increase in revenue in the second quarter from a year earlier on “increased industrial products and agricultural products freight volume” and “stronger consumer products volume.” BRK also said its manufacturing, service and retailing operation was benefiting from an improved economy. — Erik Holm