Engineering work is taking place overnight between Potters Bar and Welwyn Garden City, closing some lines.
Until approximately 05:15 on Monday morning, trains will not call at Welham Green in either direction.
Trains towards London will also not call at Hatfield.
Replacement buses will run between Potters Bar and Welwyn Garden City.
Check before you travel:
You can plan your journey using the National Rail Enquiries Journey Planner
Replacement Bus Travel Advice:
For helpful advice if you need to travel on a rail replacement service, including accessibility and bicycle information, please use this page.
You can find the location of your bus replacement by checking station signs or by searching for your station on our station information pages.
Please be advised that replacement vehicles may be busier than usual, and you should allow extra time for your journey.