If I were a congress man and I had to make a law against texting and driving the law I would make would be having the person pay a very large fine, enough to pay for there car if it was totaled and enough for 1 other car. The person then has their cell phone taken away and they get a phone that cant send texts, it can only make phone calls. They can choose not to do this but they have to do enough hours of community service to pay for their car if it were to be totaled. If the person is to cause an accident then they have to serve in jail for 5 to 10 years.
While driving being distracted can cause a bad multitude of things. The most common one being a car crash. While driving under the influence of alcohol you are very likely to be in a crash because you cannot pay very much attention to the road. While texting and driving however you are able to pay some attention to the road if you are not texting. While texting and driving you can choose not to text but while driving drunk you can not choose to become not under the influence and pay more attention to the road.
Modifying cell phones so that they can detect when they are in cars and then not be able to send or receive texts so that they people inside will not be able to text and drive. This would not reduce texting and driving, it would prevent entirely unless someone would decide it is a good idea to stick their body out of a window so that they can text while driving or riding.