to self-determination, access, professional integrity, and social implications. Specifically, a patient has a right to refuse treatment and it would be a personal assault for someone to force water on a patient, but such is not the case if a doctor merely refuses to provide lethal medication. But it also has distinctive drawbacks as a humane means of voluntary death. One survey of hospice nurses found that nearly twice as many had cared for patients who chose voluntary refusal of food and fluids to hasten death as had cared for patients who chose physician-assisted suicide. They also rated fasting and dehydration as causing less suffering and pain and being more peaceful than physician-assisted suicide. Other sources note very painful side effects of dehydration, including seizures, skin cracking and bleeding, blindness, nausea, vomiting, cramping and severe headaches. Collision with or of a vehicle Another suicide method is to lie down, or throw oneself, in the path of a fast-moving vehicle, either on the road or onto railway tracks. Nonfatal attempts may result in profound injuries, such as multiple bone fractures, amputations, concussion and severe mental and physical handicapping. Road Some people use intentional car crashes as a suicide method. This especially applies to single-occupant, single-vehicle wrecks, although some suicidal people cause head-on collisions with heavier vehicles. Even single-vehicle collisions may harm other road users; for example, a driver who brakes abruptly or swerves to avoid a suicidal person may collide with something else on the road, resulting in harm to the driver or others. Both the targeted driver and bystanders may be traumatized by the experience, even if everyone survives. The real percentage of suicides among motor vehicle fatalities is not reliably known and likely varies by the ease of accessing a car and the ease of accessing other methods. One review article suggested that more than 2% of crashes result from suicidal intent. A study in Switzerland indicated that 1% of deaths by suicide involved a motor vehicle collision. Rail On railway tracks above ground, somebody may simply lie down or stand on the tracks, as the speed of an approaching train prevents its easy stopping. This type of suicide may cause trauma for the train driver. Data gathered to 2014 showed that there were 3,000 suicides and 800 trespass-related injuries on the European railways each year. A large number of suicides in Japan every year involve the railway system.