A new Colorado “texting while driving” and “yakking on the phone while driving” law goes into effect at midnight. Starting on the 1st of December, under the new law, it is a criminal offense to text or otherwise enter data into a mobile device, from behind the wheel, while the vehicle is in motion. The new law also prohibits drivers under the age of 18 from using a cell phone at all while behind the wheel, hands-free or not.