The United States is at a crossroads in terms of its relationship with rail as a viable transportation option. With road traffic contributing to the vast majority of transportation emissions in the United States, there is no time like the present in examining whether rail will play a larger part in the US transit system in the future. This is especially important given that the US is currently more urbanized than it has ever been, with this trend expected to continue. This blog post will explore both the viability of new rail systems within cities (light rail and subways) as well as between cities (high-speed rail systems). This falls under “Shift” section of the Avoid, Shift, and Improve strategy breakdown of the transportation sector. The idea of this paradigm is to avoid using carbon-intensive transportation whenever possible. If it cannot be avoided, then shift as much transportation usage to low-carbon options as possible. And lastly, if a carbon-intensive method is still required, strive to make improvements to the technology to improve its efficiency and pollution levels.
First, American cities are no longer building subways. The last major subway system to be completed in the United States was the Washington DC system in 2001. Major metropolitan centers that have built train systems since then have opted for light rail instead. Light rail has the benefit of being much cheaper to build than drilling subterranean tunnels, which can very in expense based on the hardness of the bedrock. The major downside of light rail is that its networks are often less extensive than that of subways, meaning that they have much less potential for shifting car users to public transportation.
The main reason for this shift away from subway systems is the cost overruns of current subway system expansion projects. San Francisco’s Central Subway Project will cost $1.7 billion to cover less than 2 miles. Washington’s Silver Line is expected to cost $5.6 billion, but costs would have been even higher if plans to run certain portions of the line underground had been approved. These figures, in a nutshell, is why there’s so little subway activity in the United States. All in all, this shows that America’s major metropolitan areas will have to make serious financial investments into reducing congestion and emissions.
This issue is especially pertinent in a city like Austin, Texas that is experiencing blistering growth. Austin, like most other Sun Belt cities, has opted to construct a light rail service instead of a subway system. Rob Spillar, the director of the Austin Transportation Department, believes that the smaller pool of federal funds available for ambitious public transportation projects explains this. “When you think about cost, you have to think about how you might fund something like this,” Spillar said. “It used to be that areas could count on the federal government for paying 80 percent of the cost. Now you have to pay most of it locally. The best you can do is 50 percent. That makes you think about how efficiently we can use local dollars to get the most transit system we can get.” 
Additionally, new technologies for connecting cities to each other are on the verge of making their debut. Japan will begin constructing a new Maglev line between Tokyo and Osaka next year, which is expected to hit speeds of 315 miles per hour and shift a large portion of air travels between the cities back to rail. This is proving to be a tough sell, however, as Japan already has one of the most extensive high-speed rail systems in the world and an aging population that is expected to decline rapidly. The Japanese government has wisely realized that there is much more potential for the technology in countries that do not already have extensive high-speed railways systems. More interesting is that they have identified the eastern seaboard of the United States as one of their prime candidates.
In conclusion, there is still significant potential for shifting travelers from road to rail in America, but it will require a significant amount of foresight and investment from both regional and national policy-makers. The potential is so much greater in the US than in most other developed countries because rail commands such a small share of both intra-city commuter traffic and intercity travel traffic. Rail is still the best way to keep drivers off the road, which make up the vast majority of transportation emissions in North America. It will require extra political will in the less-congested parts of America, where car-culture has reigned supreme for most of the last century. http://blog.archpaper.com/wordpress/archives/75329  http://www.nytimes.com/2013/11/19/business/international/japan-pitches-americans-on-its-maglev-train.html?hpw&rref=&_r=0