The article discusses whether it is a good idea to electrify main train lines. In 1981, a report said it would be worth it financially. The report was made because people were worried about future energy supplies. In 2006, the idea of electrification came up again. The article updated the 1981 report to 2006-7 prices. They used four math models to compare costs of different options. They found that electrification makes more sense now than it did in 1981.