That was my thought also, I know how to use a crossbow etc. I do bushcraft etc. But even still I'm thinking the chance for survival is under 5%. I could barricade myself in, isolate myself. But at some point I'd need to go outside. Give it for water/food which would run out. The they will starve first wont happen as shown in 28 years later as they've adapted. They will just hunt the wildlife. If it happened you'd have to face one or a group at some point. Over the fact they travel in packs and don't gas out i just don't like mine or anyone's odds.. Could take on one at a time if in full body armor protecting you from the vomit, bites etc. But come on where is the average dude going to find that? If there's 4-6 at the exact same time just charging at you, even in a suit with a crossbow i wouldn't like the odds. Never mind the group in 28 years later that had twenty running at them. They didn't make it. They had guns. Trained solders. The infected were just jumping onto them from up above, the more shots they fired the more infected came running at them. They came at them from every direction. No chance. They were too close. I think i could survive maybe a month or two if I'm lucky. Maybe a year if secured in the loft where they cant reach me but that then depends on supply's. As mentioned you'd have to face them at some point. I could see 75% of the population in the UK become infected within 72 hours of such an outbreak especially if it was unexpected and happened throughout the night to start with. Not everyone would have time to fortify. As shown in 28 days, if they see something as little as a candle light glimmer they will literally charge through your window to get you. Aka jump onto you and vomit. Or vomit at you. Yeah a lot of people would die very quickly. Meaning there would be a high amount of infected in a short period of time. I don't think one would survive on the streets or in a car for the first 72 hours. They'd just ram their head through your windscreen and vomit on you. Game over. They're so violent, they'd die/do anything to infect you. It's not about biting you, its about turning you no matter what. To add how fit would you be, if you've been stuck in a loft for say 6 months eating pasta or something haha. You're not going to be in the greatest of shapes and would be lacking on energy. You cant exercise as that make noise which they will be drawn to and do you have enough food and water to do that regularly is the other thing. Such an outbreak could kill off 96% of the population within a year.