The early roads were improved by the use of tarmacadam construction in the early 20th century.
From the en.wikipedia.org
The roadway was torn up in numerous places where students had armed themselves with stones and pieces of tarmacadam.
From the guardian.co.uk
Tarmac, short for tarmacadam or tar-penetration macadam, is a type of paving material, patented by Edgar Purnell Hooley in 1901.
From the dailyherald.com
More examples
A paving material of tar and broken stone; mixed in a factory and shaped during paving
A paved surface having compressed layers of broken rocks held together with tar
Tarmac (short for tarmacadam, or tar-penetration macadam) is a type of road surface. Tarmac refers to a material patented by Edgar Purnell Hooley in 1901. ...
A mixture of tar and small stones used in paving
A paving material consisting of crushed stone covered with tar and bitumen