how to maintain interlicking driveways and walkways ?

Answer 1

Your driveway is licking your sidewalk? Oh..Interlocking!
Just pressure wash occasionaly, and sweep with stone dust. Sand will attract ants.
If they get unlevel, pull them up, level the layer of sand underneath, tamp, and re-lay pavers. Sweep with stone dust to fill the crevices.
Hint: If you add salt to the stone dust you will have fewer weeds.