What are paved Roads made of?

How many types of Roads are there? What causes a pothole? What was life like before paved Roads? 

Grown-Ups:

Be a better you in 2024 with Babbel, the science-backed language-learning app that actually works. Get 55% off at Babbel.com/SMARTED. Rules and restrictions may apply.

Say hello to HelloFresh! Go to HelloFresh.com/smartedfree and use code: smartedfree for FREE breakfast for life! One breakfast item per box while subscription is active. 

Stop wasting money on things you don’t use. Cancel your unwanted subscriptions by going to RocketMoney.com/SMARTED.