Barcodes are officially 40 years old; however, railroads have been using them for years before the official barcode terminology. Each freight car has a barcode on its side, which is scanned by trackside scanners placed at strategic points on a rail system. The scanner shows the location of the car; the railroad it belongs to; the contents and destination.In the 1960's, railroads charged each other $3.00/day to use it's tracks. side note: Chevron and Mobil oil companies are part of Aramco: Arab America Oil Companies, owned by Saudi Arabia, which also owns BNSF: Burlington Northern Santa Fe Railroad.I was a SPRINT lineman in the late 1960's a.k.a. Southern Pacific Railroad Intrastate Railroad, headquartered out of San Francisco. When I was hired at the West Oakland facility, the HR guy said "Why do you want to work for the railroad?" I said "I have always loved trains, and my hobby is model railroading." He said "You're hired."