If you want to discourage your teenager from texting while driving, make him or her drive a car with a manual transmission. A driver who has to work the gearshift constantly must stay focused. Seattle's NBC News affiliate describes how one local family uses this approach:
Riley's parents took notice of all those messages about the risks of using a phone while driving - too many sad stories. And while they trust their son, they're not taking any chances.
Riley has a smart phone, but when he gets in the car, it goes into a compartment. Blue Tooth? That might come later. But the car forces Riley to keep one hand on the wheel, and the other on the stick, especially in city traffic.
(Photo: cmonville)
Even more so, it's not necessary all the time either. On a highway you have to shift to the highest gear, keep both hands on the wheel and both eyes on the road.
Where I'm from, driving stick is taught as a standard.
If drivers don't show to be sensible in the way that you simple "can't" do anything else with your hands but driving when driving, they shouldn't be in the first place. This goes for all ages.
Having said all of the above, I totally recommend a teenager's first car should be manual transmission. Having to switch gears manually really helps you get an intimate feeling for how things work inside the engine, when you can expect power and when you shouldn't, and generally how to take advantage of a car's engine.