The first text messages were sent during 1992 and 1993, although commercially, text messaging was not widely offered or used until 2000. Even then, messages could only be sent between users subscribed to the same wireless carrier; for example, Sprint customers could only exchange messages with other Sprint customers. In November 2001, however, wireless service providers began to connect their networks for text messaging, allowing subscribers on different networks to exchange text messages. Since then, the number of text messages in the United States has grown to over 48 billion messages every month. Additionally, text messages are no longer only sent as "point-to-point" communications between two mobile device users. For example, messages are also commonly sent from web-based applications within a web browser and from instant messaging clients like AIM, MSN, or Google Chat. Short Message Service (SMS) is a method of communication that sends text between cell phones, or from a computer or handheld device to a cell phone. The "short" part refers to the maximum size of the text messages: 160 characters. The term "SMS" is generally used interchangeably with the term "text message." Even when not being used for a voice call, a mobile phone is constantly sending and receiving information. It is communicating to its cell phone tower over a control channel. The reason for this communication is so that the cell phone system knows which cell a phone is in, and so that the phone can change cells as the user moves around. Every so often, a phone and a tower will exchange a packet of data that lets both "know" that everything is working properly. The control channel also provides the pathway for SMS messages. When someone sends an SMS message, the message flows through the SMS Center (SMSC), then to the cell tower, and the tower then sends the message to the recipient's phone as a packet of data on the control channel. Figure 1 illustrates how an SMS message is processed. While SMS only allows plain text to be sent, two alternative messaging services allow for more elaborate types of messages. With Enhanced Messaging Service (EMS), formatted text, sound effects, small pictures, and icons can be sent. MMS (Multimedia Messaging Service) allows animations, audio, and video files in addition to text to be sent. As noted above, SMS messages may be sent between a computer and a mobile phone. However, these messages are sent using the e-mail address associated with the mobile device, such as 2025551212@carrier.com. For that reason, these messages are classified as e-mail and therefore are subject to different and more stringent regulation (see " SMS Spam "). Introduced in the U.S. market in October 2003, Common Short Codes (CSCs) are short numeric codes of five or six digits, compatible across carriers, to which text messages can be sent from a mobile phone. Wireless subscribers send text messages to short codes to access a wide variety of mobile content, for example, to vote for contestants on American Idol. Many entities use CSCs to communicate with interested parties: television stations; individual television shows; radio stations; instant messaging services; political, advocacy, and other organizations; magazines; and sports teams—among others. Users send a message to the CSC to subscribe to alerts or other messages. Sometimes these messages are delivered for free by the originator, sometimes there is a fee. Figure 2 illustrates how a CSC message is processed. "Vanity" CSCs are also available (for a higher price)—these CSCs use letters on a mobile device keypad to spell out words that are easy to remember and are chosen to reflect the service the short code is being used to access. Furthermore, although CSCs can be "compatible" across all carriers, some CSCs are established as business partnerships between a specific carrier and another entity. For example, American Idol has an exclusive partnership with AT&T Wireless. For congressional policymakers, the major issues that have arisen stem from what could be called "same problem, different platform." For example, issues such as consumer fraud and children's accessing inappropriate content, which have existed previously in the "wired world," have now found their way to the "wireless world." Other issues stem from the difficulty in applying technical definitions to a given service, such as whether a text message is sent "phone-to-phone" or using the phone's associated e-mail address. For example, spam sent between two phones or from one phone to many phones does not fall under the legal definition of spam; but if that same message is sent from a phone or computer using the phone's associated e-mail address, it does. According to the U.S. Department of Transportation (DOT), approximately 16% of fatalities in distraction-related crashes were caused in at least some part by mobile devices. Further, In 2009, 5,474 people were killed in U.S. roadways and an estimated additional 448,000 were injured in motor vehicle crashes that were reported to have involved distracted driving. The age group with the greatest proportion of distracted drivers was the under-20 age group—16% of all drivers younger than 20 involved in fatal crashes were reported to have been distracted while driving. Drivers who use hand-held devices are four times as likely to get into crashes serious enough to injure themselves. Using a cell phone while driving, whether it is hand-held or hands-free, delays a driver's reactions as much as having a blood alcohol concentration at the legal limit of 0.08 percent. While reading and composing text messages while driving is only one of numerous factors that can lead to distracted driving, such activity is a growing concern among safety and regulatory groups. In response to this concern, there have been various actions taken at the federal and state levels. A number of bills have been introduced in the 112 th Congress on the issue of "distracted driving." The Motorcoach Enhanced Safety Act was introduced in the Senate by Senator Sherrod Brown and in the House by Representative John Lewis on March 2, 2011. With respect to text messaging, the Motorcoach Enhanced Safety Act would require the Secretary of Transportation to prescribe regulations on the use of electronic or wireless devices (including cell phones and other distracting devices) by motorcoach operators; and prohibit their use in cases where they interfere with the driver's safe operation of a motorcoach, but not when necessary for driver or public safety in emergency situations. S. 453 was referred to the Senate Committee on Commerce, Science, and Transportation on December 14, 2011, and ordered to be reported with an amendment in the nature of a substitute favorably. The text of S. 453 was included in Commercial Motor Vehicle Safety Enhancement Act of 2011, S. 1950 . That bill was introduced by Senator Frank Lautenberg on December 7, 2011; the bill was ordered to be reported with an amendment in the nature of a substitute favorably. Senator Mark Pryor introduced Mariah's Act on July 29, 2011. The bill would create grants to states that enact and enforce a law that prohibits drivers from texting while driving; prohibits drivers age 18 or younger from using a cell phone while driving, making violation of the law a primary offense; and establishes certain minimum fines and increased civil and criminal penalties. The bill would also create a distracted driving grant program at the National Highway Traffic Safety Administration (NHTSA). The bill was referred to the Committee on Commerce, Science, and Transportation. On December 14, 2011, the committee ordered the bill to be reported with an amendment in the nature of a substitute favorably. Senator Amy Klobuchar introduced this bill on July 27, 2011. The bill focuses on teen traffic safety in general, including providing grants to educate teens on issues related to safe driving. Specifically, the bill: Directs the Secretary of Transportation to establish a teen traffic safety grant program to award formula grants to states to implement statewide programs to improve the traffic safety of teen drivers. Authorizes a state to use grant funds to implement such statewide program to improve the traffic safety of teen drivers, including activities to support peer-to-peer education and prevention strategies in schools and communities to increase safety belt use and reduce speeding, impaired and distracted driving, underage drinking, and other destructive teen driver decisions that lead to injuries and fatalities. Authorizes the Secretary to contract with a national, nonprofit organization to establish a technical assistance center to provide training and technical assistance to state and local officials, student leaders, school advisors, and other entities associated with the grant program. Authorizes the center to operate a national teen traffic safety clearinghouse. Directs the Secretary to establish the National Teen Driver Advisory Council to study and develop an education and prevention strategy to reduce teen driver injuries and fatalities. The bill was referred to the Committee on Commerce, Science, and Transportation. No further action has been taken. Representative Carolyn McCarthy introduced this bill on June 23, 2011. The act would: Direct the Secretary of Transportation to study distracted driving, including cognitive distraction when driving and driver distraction impacts on young, inexperienced drivers. Require the Secretary to withhold 25% of a state's apportionment of certain federal-aid highway program funds for the fiscal year if the state has not enacted or is not enforcing a law that (1) prohibits, except in an emergency, an operator of a moving or idling motor vehicle on a public road from using a hand-held mobile device (other than a voice-activated, vehicle-integrated, or similar device, or a global positioning system [GPS] which is not vehicle-integrated); and (2) requires, upon conviction of a violation of such prohibition, the imposition of certain minimum penalties. The bill was referred to the House Transportation and Infrastructure Committee Subcommittee on Highways and Transit. No further action has been taken. Representative Eliot Engel introduced this bill on May 5, 2011.