FOR motorists, mobile phones have been both a blessing and a curse. In 1995, when 34.5m Americans carried them, fatalities from road-traffic accidents began to fall—in part because accident victims and witnesses could immediately phone for help, says Peter Loeb, an economist at Rutgers University in New Jersey. Sadly, the trend reversed four years later. By 1999 there were 97.8m Americans touting phones, and in some cases calling and even texting while behind the wheel. The fatalities from accidents caused by drivers using phones began to outweigh the number of lives saved by the ability to summon help quickly. At any given daylight moment in America today, roughly 170,000 drivers are reckoned to be texting and 660,000 are holding a phone to an ear. Of America’s more than 35,000 annual road deaths, a quarter are now linked to phone use, according to the National Safety Council, an NGO.

It is a similar story around the world. The slaughter on the roads is often more terrible in developing countries where people may be getting their first phone and their first car, says Etienne Krug, head of injury-prevention for the World Health Organisation (WHO). In India the deadliness of drivers using phones surpassed that of drunk-driving three years ago, says Harman Sidhu, head of ArriveSAFE, an Indian pressure group. Mobile-phone distraction, he reckons, accounts for nearly a fifth of the more than 230,000 annual fatalities which the WHO estimates now take place on India’s roads.

Technology Quarterly

More than 140 countries prohibit drivers from holding a handset to their ear. Some 30 or so also forbid the use of hands-free headsets. Most modern cars come equipped with hands-free systems to make and receive calls. Yet many studies show a deeper problem is the extra cognitive workload a driver takes on when talking to another person on the telephone. Texting is even worse and is widely banned at the wheel; texters are even more likely to kill someone or die in an accident. How can technology help keep drivers focused on the road?

Caller information is already displayed on a dashboard screen by the hands-free systems in some cars. It can also be shown in the “head-up display” of vehicles which project information, such as the car’s speed, so that it appears to float beyond the windscreen. This can be less distracting because the driver does not need to adjust visual focus when looking between the road and a screen, says Sachin Lawande, a technologist at Harman, an American company which makes audio equipment for homes and cars. Such displays can also respond to gestures, like a wave of the hand, to silence a call instead of looking down for a button.

Some worry, though, that the temptation to put more information into head-up displays could lead to drivers reading e-mails, scanning calendar appointments and so forth. Better, some say, to stick to voice commands. These can be used to operate a phone no matter where it is in the car, says Peter Mahoney of Nuance Communications, an American firm which makes voice-recognition software. However, in April a study funded by America’s Department of Transportation found that speaking text messages could be as dangerous as typing them. (Nuance’s software was not used in these tests.)

A number of companies think the best tactic is simply to disable drivers’ phones. DriveScribe, an app for Android smartphones that is made by a company called Drive Power, sends out auto-replies that the driver is unavailable while a vehicle is in motion, and unblocks communications only when the vehicle stops. Mike Moen, the firm’s boss, concedes that many drivers will not willingly give up access to their devices, but says some parents require their teenage children to install the app if they wish to drive. Cheaper car insurance might persuade more drivers to accept phone-disabling features.

Another app, TextLimit, disables the touchscreen on iPhone, Android and BlackBerry devices when the GPS in the device determines that it is moving at a preselected speed, says David Meers of Mobile Life Solutions, the app’s developer, based in Atlanta. Aegis Mobility, a Canadian firm, is pursuing an alternative approach that would operate both within the phone and within the network: telecoms operators would not route calls or data to devices on the move.

But what happens if you are the passenger in a car, or on a train, and you want to talk and text? Phones in moving vehicles could be unlocked if users pass a short test, suggests Andrea Henry of Iowa’s Department of Transportation, which is planning to supply teenage drivers with Aegis Mobility’s apps. Alternatively, signals around the driver’s seat could be scrambled by a dashboard-based jammer such as the SkyBloc, made by Trinity-Noble, an American firm. It works well but may also block passengers’ phones, says Eyal Adi, head of the firm’s office in Ra’anana, Israel. Non-government use of such kit is also illegal in many jurisdictions (though a Panamanian shipping firm bought about 100 units). It seems there is no simple technological fix—unless, that is, self-driving cars become widespread, freeing drivers to use devices unhindered, and improving road safety all round