Hypersonic vactrains are widespread

Significant areas of the world have established a hypersonic, evacuated tube transport system connecting their major population centres.* Its routes primarily extend throughout Russia, Northern Europe, Canada and the US. These trains are more advanced versions of the slower, simpler prototypes first introduced decades previously.*

This form of transport works by combining the principles of maglev trains and pneumatic tubes. The trains, or vactrains as they are called, travel inside a closed tube, levitated and pushed forward by magnetic fields. After passing through an airlock, the train cars enter a complete vacuum inside the tube. With no air friction to slow it down, the vactrain can reach speeds far beyond that of any traditional rail system. The fastest routes can reach speeds of around 4,000 mph (6,400 km/h)* – or around five times the speed of sound – compared to a 300 mph maglev train a century earlier.

https://www.youtube.com/watch?feature=player_embedded&v=McpWcn-1RZU

With speed of this magnitude, any city within the network can be reached in just a few hours, even if located on the other side of the planet. A number of new routes are in the planning stages as well, including a system of truly massive transoceanic connections. This is possible thanks in part to the relative cheapness (10% the cost of high-speed rail), as well as its energy efficiency. Since the train cars simply coast for most of the trip after being accelerated, slowing down also allows most of the energy to be regained by the track system. The modular design of the tubes also enables construction to be completely automated.

One of the main issues designers had to contend with was the problem of safety. At such high speeds, even the slightest bump in the track or misalignment could end in disaster. In addition, the sheer size of the tube systems means that engineers have to deal with the movements of tectonic plates – a particular problem when crossing fault lines. In order to deal with this and disasters such as earthquakes, an immense system of gyroscopes and adjusters are maintained along the length of each route. These are controlled by an automated system of computers receiving constant streams of weather and seismic data, adjusting and bracing the track in real time. Leaks into the vacuum are managed through a combination of self-healing materials and redundant plating.

The late 21st century is a bleak, fragile time for humanity, with much rebuilding to do. However, the resurgence of international travel (following a collapse in earlier decades) is contributing once more to a homogenization between stable countries, with ease of transport bringing the world closer together. One particular area in which it helps is the rapid movement and resettling of refugees affected by climate-related disasters.