Kaifeng, as a city in China, has a relatively low crime rate. You can walk along the city streets and explore the cultural sites freely during both day and night. The locals are usually friendly and helpful, and public transport is reliable. However, like in any destination, it's crucial to be mindful of pickpocketing in crowded places and always stay aware of your surroundings. It also helps to learn some local phrases and keep emergency contacts at hand.