NH-7 is part of the North-South corridor and NH-47 is part of the Golden Quadrilateral project.
Map of the Highways in India shows the extent of coverage by these highways.
In both the highways, the work is in progress to make it 4-lane completely. The 4-lane is from Bangalore till Thoppur and then from Thumpipadi to Salem. These projects are implemented by NHAI.
A glimpse of how the highway looks (picture courtesy NHAI)