3D printing Roads around the world?

I woke up this morning thinking about this. I was watching "Savage Builds" on TV recently and they were 3D printing a titanium "Iron man Suit" at the School of Mines in Colorado. And I realized with a portable 3D printer set up like a Hybrid diesel electric or Gas electric you could generate whatever amount of electricity you wanted to use for lasers in this portable device. So, with this device you could literally fuse dirt into glass or obsidian or you could fuse rocks together to make a solid roadbed anywhere on earth or you could just use something like this to Laser groove cement already poured for better traction in rain and snow for cars and trucks to keep them from sliding off roads in the wintertime.

So, you could fuse any substance from dirt to rocks or you could groove cement roads with multiple lasers which could groove maybe 100 or more places left to right as the whole thing moves down the pavement. This could be done much quicker than methods used today for grooving and roads might be instantly ready (within an hour) ready to drive on if you were fusing rocks or dirt into solid roadbeds with lasers.