(CNN) - Riding the train has become much more popular in the United States because Americans upset with high gas prices have been taking public transit systems more often than before.
Last month, ridership on New Mexico's Rail Runner shot up 14 percent, compared to the same time last year.
In 2010, just over 10 billion public transit trips were logged. If gas remains around $4 per gallon, analysts expect that number will go up by at least 500 million.
However, experts do not expect a big increase in ridership on large public transportation systems such as New York, Boston or Chicago.