An expanse of black tarmac around a eighteen century house in the country certainly does not look the part, even if it is the most practical material.

Rolling chippings into the surface breaks up the black and help to disguise the tarmac.

It is important to choose the right type of chipping for the application. A round gravel will tend to come out under traffic a lot quicker that a angular chipping.
Also soft type of chippings will crush and powder quickly, therefore a flint gravel is the ideal type of chipping.

The higher the rate of spread of the chipping will mean the higher the proportion that will work loose from the surface. Remember there is no actual adhesion between the chipping and the tarmac, it is just punched in with the roller.

Having said all that this is becoming a very popular way of achieving a different look relatively cheaply.