From the northern terminus on the Trans-Canada Highway, Exit 75, the route loops around passing the eastern terminus of Route 144. Route 108 follows an access road built in 2003 to the former Trans-Canada Highway, then runs southeast along its old alignment to the edge of the town of Grand Falls. The road passes through the town as "Madawaska Road", passing the Grand Falls Generating Station, then the northern terminus of Route 130, and leaves along Tobique Road, then Toners Renous Road passing the Eastern Terminus of Route 105. Route 108 continues southeast through Drummond and New Denmark, Blue Bell and Hazeldean. From here, the route passes through Crombie Settlement, and Sisson Ridge then comes to a 4-way intersection at the northern outskirts of Plaster Rock with the southern terminus of Route 385. The route follows a bypass route to the south, reaching another 4-way intersection at the Route 109 junction at the south end of town. Route 108 runs east passing the northern terminus of Route 390 from Plaster Rock on the Plaster Rock-Renous Highway, a 137-kilometre road, completed in the late 1960s, through entirely uninhabited forest land that is mostly owned by J.D. Irving Limited. There are no facilities or public buildings along the route, and signs warn of "winter conditions". As the route travels towards Renous-Quarryville, it passes the southern terminus of Route 420, the route follows the Renous River as it passes through Grainfield, North Renous and then finally Renous-Quarryville coming to an interchange with Route 8, and turns northeast passing the southern terminus of Route 415 in Renous-Quarryville. The route passes through Elmtree, Upper Derby, Bryenton along a former Route 8 alignment through Derby and Millerton to its eastern end at Derby Junction at Route 8 and Route 420.
History
The number 108 was first applied to a New Brunswick road in 1965 when it replaced the former Route 22. The original routing followed the current Route 108 from Grand Falls to Hazeldean, the current Route 395 to Plaster Rock, and a road along the north shore of the Tobique River so it is very dangerous for Semi-trucks.
