Mass transit has always evolved in tandem to scientific developments. Time, energy and safety are the deciding factors of its success. A paradigm shift in terms of preference for mass transit system can be used as a proxy to measure the extent of its success.
The breakthrough in the form of jet trains and bullet trains has enabled people to commute between cities in a shorter frame of time. Energy consumption has always remained an important factor in influencing the decision regarding transportation.
Transportation has changed leaps and bounds in the last few decades. Visionaries of the modern era have always ensured we have some groundbreaking ideas that could completely change the future of mass transit if it becomes a reality.
Magnetic Levitation (Maglev) has been a breakthrough of sorts in the mass transit domain for achieving speeds above 500km/h. The most recent one to reach a speed of 600km/h was a maglev in Japan. The companies in Japan, Germany and China have been trying to improve safety features before heading towards large scale implementation. Nevertheless, lower speed versions of maglev trains have been functional in countries like Taiwan, South Korea.
The vehicle having no physical contact to the ground levitates off the guideway (similar to a rail track) by the electromagnetic forces generated by superconducting magnets placed on the vehicle and the guideway.
Maglev trains have been implemented in China and Japan, but only at a smaller scale. Availability of land, high initial investment have been the major impediments in large scale implementation of these trains.
A vactrain also called a vacuum tube train is a proposed conceptual design for very-high-speed rail transportation. It combines the idea of magnetic levitation and evacuated tubes or tunnels. The idea is to remove the resistance of air, which would enable vactrains to achieve speeds up to 4,000–5,000 mph (conceptually) while conserving energy.
Vactrains intend to use gravity to increase their acceleration. If Vac trains become a reality, it would be the fastest mode of transport overtaking the aeroplane.
While achieving the intended speeds seems far-fetched, research and feasibility studies show a possibility of reaching speeds upto1000km/h.
Hyperloop is one of the high-speed transportation idea conceived by Elon Musk.
Hyperloop consists of a low-pressure tube with capsule-like compartments moving inside them. The capsules are suspended in air, while the pressure is adjusted to provide the necessary aerodynamic lift. The magnetic linear accelerator fixed at various stations on the low-pressure tube helps control the acceleration. The rotors in the capsule enable movement.
The initial route has also been conceived theoretically with a prototype design, where the capsules that travel between Los Angeles to San Francisco. A crowd-funded group of close to 100 engineers across America, called Hyperloop Transportation Technologies, are attempting to take the hyperloop concept further, with an initiative to perform a technical feasibility study shortly.
While there has been enough research to take the mass transportations to new levels, so far only maglev trains have come closer to being practically achievable. While hyperloop has garnered a lot of attention recently, with communities across the world actively pursuing to turn it into a reality, it has had very little progress. It would take a while before it sees the daylight.
Large scale implementation is necessary to make any system viable & self-sustainable. The burden of investment in infrastructure, environmental factors and foreseeable maintenance costs in terms of tunnels (underwater/underground) appear to be the major impediments. There have also been concerns about the safety and security aspects. But these are no reasons to be less optimistic about the future as there will always be surprises one way or another.