The East-West Road, also known as the Great Road or East Road, was a dwarven-made road stretching from the Tower Hills to the Misty Mountains, ending near the High Pass.
However, by the end of the Third Age, the only frequently used portion of the road was the sliver that passed through The Shire.
History
First Age
The Dwarves built the East-West Road sometime in the First Age. In The Silmarillion, it is mentioned that the Dwarves had created "a great road that passed under the shoulders of Mount Dolmed … crossing the Gelion at Sarn Athrad." This road was soon named the Dwarf-road and was constructed shortly after the meeting between the Dwarves and the Sindar Elves in Beleriand in the year YT 1250. The portion of this road to the east of the Blue Mountains was built in the First Age and connected the Dwarf cities of Nogrod and Belegost with Khazad-dûm and the east.
After the First Age, the Dwarf-road was destroyed—along with the rest of Beleriand—during the War of Wrath. However, most of the road through Eriador survived the devastation, although it's western end was obliterated by the formation of the Gulf of Lune. It is not known how heavily it was used after the ruin of Nogrod and Belegost.
Third Age
When Arnor was established, the north-kingdom took over the preservation of the East-West Road, instituting several fortifications on or near it—including the Tower of Amon Sûl. In addition to the fortifications, Arnor expanded/constructed bridges over the rivers Brandywine and Hoarwell. After Arnor split in TA 861, the East-West Road formed the border separating two of Arnor's successor states, Cardolan and Rhudaur.
By the time of the War of the Ring in the late Third Age, the East-West Road passed through the territory of the Shire, but was little used, save by local traffic of Hobbits and Dwarves travelling between the Blue Mountains and Lonely Mountain.
After the Great War of the Ring, the part of the East-West Road that ran through the Shire became prohibited to Men, following King Elessar's proclamation.
