The Hitchin Flyover is a grade-separated single-track railway flyover on the Great Northern Route near Hitchin, Hertfordshire, England, which carries the Down Cambridge Flyover line over the East Coast Main Line. Constructed in less than a year it was built to increase the throughput at Cambridge Junction, a congested flat ("at-grade") junction with the East Coast Main Line just north of Hitchin, which put severe constraints on capacity on both that line and the Cambridge Line.