the billboard industry. Today, São Paulo is working with outdoor companies to rebuild the outdoor infrastructure in a way that will reflect the vibrant business climate of the city while adopting good regulations to control growth. Individuals and groups have vandalized billboards worldwide. Road safety concerns The most comprehensive review of the literature to date by the Centre for Accident Research and Road Safety-Queensland (CARRS-Q) found that crash risk increases by approximately 25-29% in the presence of digital roadside advertising signs compared to control areas. There is an emerging trend in the literature suggesting that roadside advertising signs can increase crash risk, particularly for those signs that have the capacity to frequently change (often referred to as digital billboards). In the US, many cities enacted laws banning billboards as early as 1909 (California Supreme Court, Varney & Green vs. Williams) but the First Amendment has made this difficult. A San Diego law championed by Pete Wilson in 1971 cited traffic safety and driver distraction as the reason for the billboard ban, but was narrowly overturned by the Supreme Court in 1981, in part because it banned non-commercial as well as commercial billboards. Billboards have long been accused of distracting drivers and causing accidents. This may not necessarily be true, as a study by researchers at the University of North Carolina showed. Released in June 2001, the researchers prepared a thorough report on driver distraction for the AAA Foundation for Traffic Safety. This study said: "The search appears to suggest that some items—such as CB radios, billboards, and temperature controls—are not significant distractions." Traffic safety experts have studied the relationship between outdoor advertising and traffic accidents since the 1950s, finding no authoritative or scientific evidence that billboards are linked to traffic accidents. However, many of these studies were funded by the Outdoor Advertising Association of America, which has led to accusations of bias. The methodology used in certain studies is also questionable. The US Department of Transportation, State Department of Transportation and property/casualty insurance companies statistics on fatal accidents indicate no correlation between billboards and traffic accidents. A broad sampling of law enforcement agencies across the country found no evidence to suggest that motor vehicle accidents were caused by billboards. Property and casualty insurance companies have conducted detailed studies of traffic accident records and conclude no correlation between billboards and traffic accidents. However, studies based on correlations between traffic accidents and