The Rosby road is a road in the crownlands running from the Iron Gate at King's Landing through Rosby to Duskendale. After Rosby, the road to Duskendale passes apple orchards and fields of barley and becomes rutted. The Duskendale road then heads north to Maidenpool.
During the Dance of the Dragons, Queen Rhaenyra Targaryen fled King's Landing after the Storming of the Dragonpit. Her party was barred at the gates at Rosby and were allowed to stay a single night at Stokeworth. Half of her gold cloaks abandoned Rhaenyra during their journey toward Duskendale, and the queen's camp was attacked by broken men one night.
A Clash of Kings
As Hand of the King, Tyrion Lannister has Ser Jacelyn Bywater and the gold cloaks lay a trap on the Rosby road for Ser Boros Blount of the Kingsguard. who is leading an escort for Prince Tommen Baratheon and Lord Gyles Rosby. Ser Jacelyn takes Tommen without a fight and into Tyrion's protection at Rosby, rather than Queen Regent Cersei Lannister's, and he replaces the Rosby garrison with fifty of his best men.
A Feast for Crows
Brienne of Tarth takes the Rosby road toward Duskendale when she begins her search for Sansa Stark. She leaves Ser Illifer the Penniless and Ser Creighton Longbough in the middle of the night at the Old Stone Bridge.