Ball park numbers:
to 25 000 sq miles = 90 bn square meters.
At about 4 tiles per m2, thats 240 billion tiles.
At 50 LEDs each, thats 12 trillion LEDS.
These need to be light up ALL the time you want road markings!
300 LEDs takes about 60 Watts.
Cheap electricity is about 0.06 dollars per kW Hr
So to run 300 LEDs for 1 hr coast about half a cent.
To run 12 trillion LEDs for 1hr costs about 150 million dollars!
4 billion dollars per day,
1.4 trillion dollars per year.
They will take more power just to run the LEDs than will be generated by the road!!!
And thats not including the cost of building the infrastructure, or the fact that the LED probably will need to be replaced about every 5 years.