Texting lane a self writing joke?

People who text while walking are so much of a nuisance that cities are considering marking lanes on the sidewalk for people who want to text while walking. This is true. Why? People who text while walking are more distracted, so they tend to walk slower. That way, they can have a place to walk slower while everyone else walks normally. And this is going to get worse as more people have smartphones. Now it's texting but people will just walk and use their phones to play games, read facebook and general not care about other people. 

I can see this not solving the problem totally. You see, while walking and texting in a lane will make it safer for them to do so without bumping into people walking the other way, it still won't stop you from bumping into the person in front of you. Until someone writes an app to track the guy in front of you via GPS and display a warning when he slows down. I will write an app that interrupts the use with the message LOOK UP every 5 seconds. How will this work? The message won't go away until you actually look up. The app knows because of the camera watching you. 

This will all lead to all sorts of shenanigans. People who hate the people who text while walking will just draw a fake texting lane leading to an open manhole. People will just walk and drop in like lemmings. Is that the way these lanes will solve the problem of people texting? By getting rid of them?