Leave it to Terraria to make even laying a ground surface interesting. Asphalt is a great ground material in the game. When your player runs along it, they are able to move much faster than when on other surfaces. Fortunately, this material is quite easy to make, but takes some time to get what you need to make it.
How to Make Asphalt in Terraria
It should be said right away that Asphalt is a Hardmode material, so the Wall of Flesh must be defeated before this even becomes available to you. Even then, more requirements have to be met before you can manufacture this material yourself.
When you defeat one of the three Mechanical Bosses, be it The Twins, Skeletron Prime or The Destroyer, a new NPC vendor will appear. She is the Steampunker, and will stay in your base provided she has a valid House to occupy. She has a particular device you will need to make Asphalt, and that is the Blend-O-Matic. For a not-cheap price of 10 Gold, she will sell you one. At this point in the game, unless you spent crazy amounts of money, this shouldn’t be too hard for you to come up with. As for the Blend-O-Matic itself? It’s entire purpose is simply to make Asphalt. That’s quite literally all it can do.
Fortunately, the material to make Asphalt is extremely common. Only requiring two Stone Block and one Gel, the Blend-O-Matic will make an Asphalt Block. You should have thousands of both material available to you at that point in the game. With such common ingredients, you can lay down fast track Asphalt surfaces across long distances with ease. The increased speed on this surface stacks with speed-enhancing equipment like the Lightning Boots. So for long straightaways, Asphalt will make traversal much faster throughout your world.
We got plenty more Terraria help where this came from!