Why Saudi Arabia Is Building a Linear City

I live in Brasilia, and i like so much the advantages in mobility and ease of navigation thru the city with this layout. but it was never planned the growth of the city, resulting a lot of traffic jam, strangled spots that were planned solely to the internal population of the city. Adding the satelite cities the capital can't handle the ammount of cars from them. they where plans to extend the metro line on the axis but government screw every time. I think that arabs will do very sucessfull.