Depending on the meaning:
* Direction: If you're talking about the act of guiding or pointing towards something.
* Straightforwardness: If you're talking about being clear and easy to understand.
* Directness: If you're talking about the quality of being direct and straightforward.
* Control: If you're talking about having direct control over something.
* Route: If you're talking about a direct path or journey.
* Line: If you're talking about a direct connection or relationship.
Example:
* The teacher gave clear directions for the assignment. (Using "direction" to refer to guidance)
* I appreciate her straightforwardness in her communication. (Using "straightforwardness" to refer to clarity)
* He was known for his directness, even when it was uncomfortable. (Using "directness" to refer to the quality of being direct)
The best noun to use will depend on the specific meaning you want to convey.