From CryptoWiki

"A roadmap is a strategic plan that defines a goal or desired outcome and includes the major steps or milestones needed to reach it. It also serves as a communication tool, a high-level document that helps articulate strategic thinking — the why — behind both the goal and the plan for getting there."

Many crypto projects have roadmaps on their website. Some more believable than others. It is understandable that projects working on highly experimental technology have difficulty with predicting their milestones. However if projects do follow their promised roadmap it is often used measure of success.