They went through the region of Phrygia and Galatia and were prevented by the Holy Spirit from speaking the message in the province of Asia.
When they came to Mysia, they tried to go into Bithynia, but the Spirit of Jesus did not allow them.
So, bypassing Mysia, they came down to Troas.
During the night a vision appeared to Paul: a Macedonian man was standing and pleading with him, "Cross over to Macedonia and help us!"
After he had seen the vision, we immediately made efforts to set out for Macedonia, concluding that God had called us to evangelize them.
References for Acts 16:10