The vast majority of modern road infrastructure in Ontario was built throughout the 1950s, 1960s, and early 1970s. The cancellation of the controversial Spadina Expressway and the introduction of the Environmental Assessment Act in the 1970s resulted in a decline in new highway construction in the decades since. In the late 1990s, nearly of provincial highways were transferred, or "downloaded" back to lower levels of government. Few new provincial highways have been built in the early years of the 21st century, although several major infrastructure projects including the Herb Gray Parkway and expansion of Highway 69 have proceeded.