>>1775296The western third of the US is full of gravel Forest Service, logging, and utility access roads, often very close to the cities and towns where most people live. They're amazing places to ride, and yes, you can enjoy a lot of them on ordinary road bikes if you're already fit and have good handling skills, but purpose made modern "gravel" bikes that come stock with lower gearing and wider tires make these amazing experiences practically accessible to many more riders.