Roads, railway lines, and above all, highways are the largest hurdle to animals. Line investments fragment the environment which leads to decreasing natural areas inhabited by animals and breaking their migration routes. Thus, biotypes are isolated and there is no biological exchange between distant populations which results in weakening and degeneration of animals. This occurs especially in large ungulates (deer, roe deer, wild pigs, elks). Roads and highways lessen or prevent animal migration. Based on studies conducted in Switzerland, the article discusses constructing special sections where animals could cross highways.