BOISE, Idaho (AP) — Environmental groups, the Nez Perce Tribe and the U.S. Forest Service have agreed to a settlement in a lawsuit over huge "megaload" shipments.

Shipments of the very large truck loads have been on hold along a 100-mile stretch of U.S. Highway 12 between Lewiston, Idaho and the Montana border. The settlement means historic oversized loads, including big logging and farming trucks, can continue on Highway 12, but future megaloads are banned from the road.

Megaloads became a point of contention about six years ago when ConocoPhillips and ExxonMobil got permits to transport massive pieces of oil refinery equipment to the Canadian tar sands. The loads were sometimes big enough to block both lanes of traffic, and critics raised several concerns about environmental impact and residential access.