Ever want to monitor the bus you're riding in up-to-the-minute fashion? There's a new app for that, and it allows you to check the safety record of a bus company before booking that summer trip.

The National Transportation Safety Board says discount bus lines are one of the fastest growing modes of transportation, but they are seven times more dangerous than the bus lines that run between traditional bus terminals.

In cities like Washington DC, dozens of people can be seen queuing up Friday after work in historic DuPont circle for a $25 trip to New York City, and there are popular discount bus companies operating between numerous other cities, such as Los Angeles and San Francisco or Miami and Orlando.

As the summer months approach and vacations are planned, these lines will undoubtedly get longer and although the app can't tell you where the longest line will be, it can tell you which of the bus companies is the safest.

The safety of these buses came into question last year when two were involved in crashes, one includind a fatality.

Today the Federal Motor Carrier Safety Administration (FMCSA) unveiled its SaferBus application, which allows motor coach riders to check the safety record of a bus company before booking their ticket.   You can even make a complaint about the bus you are riding, while you are riding it.

"This new app gives Americans the information they need to make smart safety decisions when they book their next bus trip," Transportation Secretary Ray LaHood said in a statement to ABC News.  "As college students, families and tour groups start thinking about spring and summer travel, we encourage everyone to use the SaferBus app to look before you book your next bus trip."

With gas nearing $4 a gallon and expected to continue moving up into the summer travel season, buses are often used as a cheaper travel method. With some companies offering deals as low as $1, like the BoltBus from DC to NY, it's easy to see why.

" SaferBus is FMCSA's first step at making our thorough safety data on commercial bus companies available through smartphone technology," FMCSA Administrator Anne S. Ferro said in a statement to ABC News. "By placing a bus company's safety record in the palm of your hand, SaferBus encourages riders to think safety first, supports our agency's commitment to make bus travel as safe as possible, and provides good bus companies a way to highlight their positive safety records."

The free app, the FMCSA is touting as "first of its kind," provides safety records for nearly 6,000 interstate commercial passenger carriers operating in the United States today

This app comes after a report released last October by the NTSB highlighted key safety issues, including high accident rates.

Curbside motorcoach operations are described as scheduled trips that begin or end at locations other than traditional bus terminals; an example are the often used providers that run between DC/New York City, LA/San Francisco, and  Orlando/Miami.

One key finding of the report showed from January 2005 to March 2011 the fatal accident rate for curbside carriers from was 7 times that of conventional bus operations (about 1.4 fatal accidents per 100 vehicles).   In addition, the report highlighted that FMCSA is overburdened having only about 1 inspector for every 1000 motorcoaches.

"Business and safety practices within the growing curbside bus industry create challenges for enforcement authorities and consumers alike when it comes to separating the safe operators from the unsafe operators," Hersman said during last year's press conference.

The app is available for iPhone and iPad users and can be downloaded from the iTunes store or from FMCSA's "Look Before You Book" webpage.