and retail merchants. mobile tracking mobile phones are commonly used to collect location data. while the phone is turned on, the geographical location of a mobile phone can be determined easily (whether it is being used or not) using a technique known as multilateration to calculate the differences in time for a signal to travel from the mobile phone to each of several cell towers near the owner of the phone. the movements of a mobile phone user can be tracked by their service provider and, if desired, by law enforcement agencies and their governments. both the sim card and the handset can be tracked. china has proposed using this technology to track the commuting patterns of beijing city residents. in the uk and us, law enforcement and intelligence services use mobile phones to perform surveillance operations. hackers have been able to track a phone's location, read messages, and record calls, through obtaining a subscribers phone number. while driving a driver using two handheld mobile phones at once a sign in the us restricting cell phone use to certain times of day (no cell phone use between 7:30–9:00 am and 2:00–4:15 pm) mobile phone use while driving, including talking on the phone, texting, or operating other phone features, is common but controversial. it is widely considered dangerous due to distracted driving. being distracted while operating a motor vehicle has been shown to increase the risk of accidents. in september 2010, the us national highway traffic safety administration (nhtsa) reported that 995 people were killed by drivers distracted by cell phones. in march 2011, a us insurance company, state farm insurance, announced the results of a study which showed 19% of drivers surveyed accessed the internet on a smartphone while driving. many jurisdictions prohibit the use of mobile phones while driving. in egypt, israel, japan, portugal, and singapore, both handheld and hands-free use of a mobile phone (which uses a speakerphone) is banned. in other countries, including the uk and france and in many us states, only handheld phone use is banned while hands-free use is permitted. a 2011 study reported that over 90% of college students surveyed text (initiate, reply or read) while driving. the scientific literature on the dangers of driving while sending a text message from a mobile phone, or texting while driving, is limited. a simulation study at the university of utah found a sixfold increase in distraction-related accidents when texting. due to the increasing complexity of mobile phones, they are often more like mobile computers in their available uses. this has introduced additional difficulties for law enforcement officials when attempting to distinguish one usage from another in drivers using their devices. this is more apparent in countries which ban both handheld and hands-free usage, rather than those which ban handheld use only, as officials cannot easily tell which function of the mobile phone is being used simply by looking at the driver. this can lead to drivers being stopped for using their device illegally for a phone call when, in fact, they were using the device legally, for example, when using the phone's incorporated controls for car stereo, gps or satnav. a 2010 study reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety. in 2013, a national survey in the us reported the number of drivers who reported using their cellphones to access the internet while driving had risen to nearly one of four. a study conducted by the university of vienna examined approaches for reducing inappropriate and problematic use of mobile phones, such as using mobile phones while driving. accidents involving a driver being distracted by talking on a mobile phone have begun to be prosecuted as negligence similar to speeding. in the united kingdom, from 27 february 2007, motorists who are caught using a hand-held mobile phone while driving will have three penalty points added to their license in addition to the fine of £60. this increase was introduced to try to stem the increase in drivers ignoring the law. japan prohibits all mobile phone use while driving, including use of hands-free devices. new zealand has banned hand-held cell phone use since 1 november 2009. many states in the united states have banned texting on cell phones while driving. illinois became the 17th american state to enforce this law. as of july 2010, 30 states had banned texting while driving, with kentucky becoming the most recent addition on 15 july. public health law research maintains a list of distracted driving laws in the united states. this database of laws provides a comprehensive view of the provisions of laws that restrict the use of mobile communication devices while driving for all 50 states and the district of columbia between 1992 when first law was passed, through 1 december 2010. the dataset contains information on 22 dichotomous, continuous or categorical variables including, for example, activities regulated (e.g., texting versus talking, hands-free versus handheld), targeted populations, and exemptions. while walking people using phones while walking in 2010, an estimated 1500 pedestrians were injured in the us while using a cellphone and some jurisdictions have attempted to ban pedestrians from using their cellphones. other countries, such as china and the netherlands, have introduced special lanes for smartphone users to help direct and manage them. health effects main article: mobile phone radiation and health