I discovered this video while mining for Salem content in the Youtube.com servers.
Here's a copy and paste from a 2008 traffic impact analysis that I discovered while searching for info. For the whole report, PDF click here.
White Cloud Properties proposes to develop a 260 acre quarry on 700 plus acres west of the intersection of Skyline Road at Setting Sun Road in southwest Marion County, Oregon. The remaining 440 acres will serve as a buffer for the mining area. The quarry will transport rock products from the site by rail which currently runs along the southwest boundary of the site and by truck using an improved access at Setting Sun Road at Skyline Road. There is adequate capacity (volume) on the roadways to and from the White Cloud Quarry to serve vehicles traveling to and from the quarry. It is noted that the quarry will not operate trucks. This study will assume that there are 3 employees (6 trips) traveling to the quarry each day and 10 other trips to or from the quarry to repair or deliver
equipment and 50 loads of rock (100 trips) hauled from the site each day. With anticipated growth there will continue to be adequate capacity on the roadways and intersections for the next 20 years. Skyline Road and Riverside Road are thought to be the primary travel routes for employees, trucks and vendors to the quarry. These roads are like many old county turnpike roads built before current geometric standards were developed.
There are heavy trucks using these roads currently and the crash data from ODOT indicates that in the 13 reported accidents in the 5 years between 2002 and 2006, neither of the two truck drivers in the two accidents involving a truck was cited for an error. The roads are rural and crooked in some sections, some intersections are skewed, but Marion County has placed restrictions to improve service and safety of these roads. The intent of this analysis is to provide decision makers transportation and traffic information to demonstrate the PAPA application for the White Cloud Quarry should be approved. A geological assessment estimates there are more than 20,000,000 tons of high value rock products on the site. The Columbia River Basalts Group rocks "make excellent raw materials for road construction
There is a group fighting this development, here's there website.