The aggregate is whatever is near by to harvest. Interstates are no difference in pavement design other than consideration for % trucks.
I thought it came from Quarry's where it can be crushed to what ever size is ordered?
The grade of asphalt Oklahoma uses is K if my sources are correct. . The bottom of the barrel as far as asphalt grades are concerned.
Other states use a higher mix of Bitumen to obtain a higher grade of road surface?
I have driven Ks Hwy 166 from Arkansas city to Joplin Mo for 20 some years. There is not a single pot hole on that road or any evidence of a patch. Its also mostly a light tan to white. Great drivability at night. Oklahoma black roads get pot holes patched within months of installation.
Why can't Oklahoma mimic what our neighbors do?