There's a lot of excessive paranoia in the United States about areas like Compton. I'm not saying that such areas are places that you'd really want to stop for lunch, or walk through after dark (or even before dark, in some cases), but the idea that you're going to get strafed with gunfire just driving through is pretty silly.
I live in a city--Baltimore, Maryland--that perennially has one of the highest murder rates in the nation. There are parts of this city that really are very dangerous places. If you walk around those places, even during the day, there's a pretty decent chance that someone will stick a gun in your face and demand your wallet. This is especially likely if you obviously don't fit in, which, in the case of Baltimore's poorer neighborhoods, would generally apply to anyone who's not African American.
I guess it's also possible that you might run into trouble driving through those areas, but i've driven through them during the day and never encountered any trouble. I have gotten a few hard stares from people on the street, but while they don't exactly seem like friendly stares, they also don't look like they're about to jump into a car and chase me down with guns blazing. It always seemed like sort of a "What are you doing here? Just keep moving!" sort of stare.
The fact is that, while Baltimore is a violent city, a large majority of the murders and other violence tends to occur between people who know each other, and who have particular reasons for animosity. A lot of the murders are drug-related (Baltimore has a huge heroin problem), with drug dealers and gangs protecting turf. There are also neighborhood disputes that can escalate into violence and gunfire. Some people also get killed for talking to the police; there's a real culture of "don't snitch" in some Baltimore communities.
If you take a map of Baltimore and insert a pin for every murder, you'll find a few large concentrations in East Baltimore and West Baltimore, which are the poorest parts of the city. Most of the people in these neighborhoods are just poor folks trying to get by, but they often get caught up in the violence for no reason, or because they try to improve their neighborhoods. A few years ago, a family tried reporting drug activity to the police, and in retaliation their house was firebombed twice. The first time they got out; the second time both parents and their five children died in the blaze.
Link
Over the past few years the city has averaged about 265-275 homicides a year in a population of about 680,000. By comparison, in the 12 months from June 2005 to June 2006, the UK had 765 murders in a population of over 50 million, and that number was inflated by the 52 victims of the London bombings in July 2005.
Of Baltimore's 275 homicides in 2006, 254 of the victims (and a similar percentage of the perpetrators) were African American, overwhelmingly men in the 16-30 years age group.
Link We're on pace for about 305-310 murders this year.
If you don't live in the poorest neighborhoods, you have a pretty small chance of being killed. Your most likely encounter with crime would be getting held up on the street and told to give up your wallet and cellphone. And that happens in good neighborhoods and bad, because Baltimore is very much a city of relatively small neighborhoods, and poor neighborhoods often run right alongside wealthy ones.
I live near Johns Hopkins University, in a neighborhood populated mainly by college students and white middle class professional types in apartment buildings and medium-sized row houses.
Here is a panorama (warning: uses Java plugin) of our street in winter. Just to the north of us is one of Baltimore's toniest and most expensive neighborhoods, with large freestanding homes on big leafy blocks of land. To the east is a relatively poor and working class black community. There is another similar neighborhood to the south, and over to the west is a poor black community and a working-class-but-rapidly-gentrifying white neighborhood.
If someone from one of the poorer communities decides that he needs to rob someone to get some money, he's most likely to go where the money is--the wealthier neighborhoods. There are usually one or two armed hold-ups a month within ten or fifteen blocks of my house. Last month, there was one about 20 metres from our front door. You have to be careful walking around alone at night, although the crime reports about these incidents suggest that if you calmly hand over your wallet or purse then you won't come to any further harm. They generally just want the money.
Anyway, i guess that all makes it sound like Baltimore is a scary place to live, but it's really not. If you let yourself get paranoid about this stuff, you'd never leave the house and would live a miserable life. It's true that you have to be a bit careful about walking around, and you need to be aware of your surroundings, but it's not like living in a war zone, as long as you're not confined by poverty to the very poor, very dangerous neighborhoods.
I guess that some of those places are a sort of no-go zone for a middle-class white guy like me, because i would stick out like a sore thumb and be likely to attract the attention of someone looking for trouble. Also, because those neighborhoods are so poor and run down, there's generally not much to attract people to them anyway. But i think it's worth remembering that, even in the poorest and most dangerous areas, the majority of people aren't criminals; they're just poor people doing their best to get by under very trying circumstances.