In the United States, the Virginia Tech Transportation Institute has conducted a number of naturalistic studies of driving behaviour. Some researchers have looked at real-world driving in instrumented cars, on closed test-tracks or even on public roads. A number of studies have investigated how drivers' eye movements are affected by phone-use and some have used EEG equipment to examine the effects of phone-use on brain activity. David Strayer and his colleagues at the University of Utah have compared mobile-phone-use to other potential distractors. If mobile-phone-use affects performance so badly, why do drivers do it? Phone-use remains widespread, despite publicity campaigns warning of the dangers and media coverage of fatal accidents caused by drivers on mobile phones. As with mobile phones, drivers try to ameliorate the risks by texting only when stationary, such as at traffic lights, or when they perceive the road conditions to be "safe".