with the cities of Westminster, Arvada and Golden to do an environmental impact study, the first step in an attempt to complete the beltway by 2020. The last segment of the beltway would be another tollway, tentatively called W-470, and would connect the west end of the Northwest Parkway to the northwest end of SH 470 but was later rejected and cancelled. The same plans to complete the beltway later reemerged and were to call the last section the Jefferson Parkway which is to begin at the Northwest Parkway and end at the west end of SH 470. Jefferson County, Broomfield and Arvada have formed the Jefferson Parkway Public Highway Authority to construct the freeway. If the 20-mile parkway is constructed, Denver will be completely encircled by a "metropolitan beltway." In February of 2020, Broomfield notified Arvada and Jefferson County of plans to exit the Authority. After 12 years of being in the Jefferson Parkway Public Highway Authority, Broomfield opted out after citing an elevated reading of plutonium in the proposed path of the tollway, where the former nuclear weapons manufacturing plant was along the Rocky Flats National Wildlife Refuge. Opposition also grew in Arvada as concerns for excavating decades-old plutonium as well as noise impacts, air and light quality, and debris flying into people's yards from high speed traffic. Exit list Controversy The completion of the freeway has been mired in controversy. In 1975 Colorado Governor Dick Lamm vowed to "drive a silver spike" through the plans for the road. In 1989 voters turned down an expansion of the freeway by a four-to-one margin. In the late 1990s a citizens group called Citizens Involved in the Northwest Quadrant (CINQ) was formed to oppose the completion of the freeway. In 2008, a group of Arvada residents sued to try and stop the city from joining the newly formed JPPHA. Notes See also References External links Denver's 470 Saga Colorado Highways: Routes 400 to 789 470 Transportation in Jefferson County, Colorado Golden, Colorado Transportation in Douglas County, Colorado Colorado State Highway 470 Transportation in Lakewood, Colorado Littleton, Colorado Interstate 70 Beltways in the United States