In the 18th and early 19th centuries, railroads became the most important means of long- distance land transportation.
Most countries have updated their railroad infrastructure as their economies grew. However, in a few countries, the economy has grown much faster and the infrastructure has not been able to keep pace, e.g. China, where demand far outstrips supply in terms of rail transportation. China's network satisfies only 60 percent of current demand. The Chinese government has pledged to spend more to improve current railroad infrastructure like the “one belt one road” initiative. The one belt one road initiative is now referred to as the Belt and Road Initiative (BRI).
Over the years, as roads and trucks improved, many countries' railroads gradually lost their focus on shipping cargo and shifted their efforts to high-speed passenger transportation. Some improvements to rail infrastructure include increasing the height clearances in tunnels and other areas, allowing trains to transport containers "double-stacked".