Reply to comment by adfthgchjg in TIL of Macadam roads. These roads were convex, raised a few inches, and made of layered crushed rock; they were state-of-the-art for the 19th century. The rise of automobiles led to the dust issues that were solved by binding the roads with tar, leading to the invention of tarmac. by jamescookenotthatone

Reply to comment by mrsc1880 in TIL of Macadam roads. These roads were convex, raised a few inches, and made of layered crushed rock; they were state-of-the-art for the 19th century. The rise of automobiles led to the dust issues that were solved by binding the roads with tar, leading to the invention of tarmac. by jamescookenotthatone