 The boom years were 1836 and 1845–47, when Parliament authorized 8,000 miles of lines at a projected cost of £200 million, which was about the same value as the country's annual Gross Domestic Product (GDP) at that time.A new railway needed an Act of Parliament, which typically cost over £200,000 (about $1 million) to obtain, but opposition could effectively prevent its construction.The canal companies, unable or unwilling to upgrade their facilities to compete with railways, used political power to try to stop them.