You don't have to put LEDs in to digitally stripe the roads. It would be cool to have roads that could play messages or change configurations but it's not necessary. Use a paint that allows sunlight to penetrate and you could stripe the roads much cheaper than installing LEDs.
While you are at it, you could install robotic control systems and true robot cars would finally be feasible. It's possible to build a robotic car now. All that's needed are controls in the roads to monitor and control traffic. HUGE costs involved but technically possible right now.
Will this be done?
No. No politician would ever put their name on a project that would cost trillions. Maybe, in the future, roads like this will be built... once costs are lessened to below current/future road construction costs but not before then.