I don't think this is a realistic example and it especially does not draw any attention to the reasons why people think they can get away with texting. The real nature of texting while driving is that you perceive a specific period of time during which it will be safe to accomplish a very familiar, tactile task. You text during the times you perceive safety (for example, at a stoplight) and focus on driving otherwise, performing only the simplest of phone tasks when driving is more difficult. The danger is as much that those predictions about the road fail and you're not as good at the phone tasks as you think, than the raw inability to multitask.

This test was unrealistic because the road challenges were almost entirely unpredictable, and because using the phone involved learning something new (I can in fact accomplish a number of tasks on my phone without even looking at the display). The phone in the example required a great deal more attention than I have to give to a typical text message.