It is true that using smart phones while driving can cause harmful effect for drivers and I firmly believe that, it should be made restricted. As it has been seen that majority of the accidents happen because a driver use mobile phone while driving.
We all know that driving requires attention and when a driver use smart phones, its distract them from driving and lead to the accident. Moreover, It is not always caused a damage to that particular driver only, but also a passengers who are in that car too. To prevent such kind of incidents, there should be a law which prevent drivers from using cell phones while driving. Additionally, government should spread awareness about not using mobile while driving by organizing events. Also, they should start giving fines to the drivers who are not understanding the seriousness and keep doing this kind of activity while driving.
However, some people argues that, they have to check their mobile while driving as they might have received some important call or message. In this case what I suggest is, to connect their phone with Bluetooth so they do not have to look in to their phones while driving. Although, there are few cases which would be exceptional, For instance, if someone in the car is having medical condition than a driver can call emergency services while driving.
To end with, my stance is using mobile phone while driving should made illegalized as it caused harm to the drivers as well as other drivers who are on that road too.