In Middle-earth during the Second and Third Ages, there were several roads of great import to travellers. It is safe to assume that these were the lifelines of trade and communication between kingdoms. They were:

• The North-South Road (also known as the Great Road, the West Road, and the Royal Road), which connected Arnor and Gondor. This road began at Fornost and headed south, where its first junction point with any other populated area was Bree. It passed through the Barrowdowns and the White Downs, which were to the west and east of it. Then, after turning southeast, it made its first river crossing at Tharbad, which was a small port-town on the banks of the river Gwathló. It passed through the region known as Enedwaith, to the west of Dunland and Isengard, eventually crossing water again at the Fords of Isen, which were located in the Gap of Rohan. This took the road in east, but only for a short while. It took up the southeast direction again, with shorter diverging roads leadings to Helm's Deep and Edoras in the southwest. The road leading to Helm's Deep was known as the Deeping Road. The Great Road then stayed close to the mountain range of Ered Nimrais (Helm's Deep and Edoras were both nestled into the northeast side of this range) until it reached Minas Tirith. It went further to the east, meeting Osgiliath and running to Minas Ithil, but once Osgiliath was destroyed and Minas Ithil was taken by the Nazgûl (after which it was renamed Minas Morgul, the road fell into relative disuse, except for purposes of military maneuvers. When it reached Minas Morgul, the Great Road met a shorter road running north-south, which went through North Ithilien to Morannon the Black Gate in the North, and off through South Ithilien to the southern land of Harad after crossing the river Poros. Also, another road left Minas Tirith and headed south to the port town of Pelargir, then turning back to the northwest and into the region known as Lamedon.
  
• The East-West Road, or simply East Road, which ran from Mithlond, through the Shire and into Imladris. It crossed the Baranduin, travelling north of the Old Forest, and intersected with the Great Road at Bree. Then it passed south of Amon Sûl and the rest of the Weather Hills, crossing the rivers Mitheithel and Bruinen, and coming to its end at Imladris, the home of Elrond.
  
• The Old Forest Road, which was also called the Forest Road, and Men-i-Naugrim or the Dwarf Road. This road began at the Old High Pass in the Misty Mountains and crossed the Old Ford at the river Anduin. Then it went through Mirkwood forest, ending at the Celduin, also known as the River Running, which led north to the Long Lake, Esgaroth and Erebor, and south to the Sea of Rhûn.
  
• There was also another road (without name) heading southeast out of Hobbiton, crossing the Baranduin at the Sarn Ford, and met up with the Great Road south of Bree.

All of this information was taken from J.R.R. Tolkien's Unfinished Tales, specifically page 462 in the index, and the maps at the back of the book. This edition of Unfinished Tales was put out by Unwin Paperbacks in London, England, and published in 1980.