Many states have laws prohibiting texting and handheld devices, but it is a patchwork of laws with different levels of enforcement. According to the Governors Highway Safety Association, only nine states plus Washington D.C. require drivers to use hands-free devices. Some states, like Hawaii, have no ban, but every county has a distracted driving ordinance. While that purports to do the same thing, the enforcement is a bit more subjective.
Illinois bans hand-held devices when driving through school zones or construction zones, but Main Street is fair game. South Carolina, Texas, Utah, New Hampshire, and other states have their own twist on distracted driving and cellphone use. You can see it quickly gets tough to figure out what the law is in a given jurisdiction.
Making the issue even worse is another layer on top of that aimed at novice drivers, which are those who are under 18, have a permit, are in their first year of driving, or have a combination of two or more of those conditions.
Texting laws have their own maze of rules and regulations. Quick--what is the law in your state for texting and handheld devices? Check out the chart to see if you are correct.
The issue here is being distracted while moving down the road at 50 mph. Traveling at that speed you are covering just over 73 feet per second. A five-second distraction is 367 feet--more than a football field. That's about how long it took you to read this sentence, which would easily fit in a text message. If you had to unlock your phone to read the message and you reply with a quick "ok," the amount of attention being diverted away from driving goes up exponentially. At 70 mph on the interstate, you cover over 500 feet in the same time. A lot can happen in that distance.
The NTSB has no actual authority to implement such a ban. It is only an advisory board. The federal government, likewise, has limited authority over the states. However, it carries a big stick in the way of funding. To get uniform laws passed in all 50 states, the federal government just has to withhold federal highway funding. This is how a national 55 mph speed limit was enacted in the 1970s.
Note that while the NTSB has no actual authority, its recommendations carry a lot of weight. Most of its recommendations are carried out. Highway laws passed due to NTSB recommendations include age 21 drinking laws, high-mount brake lights, and the commercial drivers' license. Expect the cellphone ban proposal to get some traction quickly.
It looks like we may lose some of the productivity gained in the past 10 years from people doing work behind the wheel. Somehow though, the world managed to work in the decades before widespread cellphone usage. It is a question of what is more important, a human life or a closing a deal at high speed rather than pulling into a Starbucks to hammer out the final details.