Why do some British trains still rely on old levers?

At Network Rail's Manchester classroom, I learn why it's very rare for trains to collide... and try out signalling for real. | ▶️ The next episode is on Nebula right now: https://nebula.tv/videos/tomscott-can... | 🗺️ England series map: https://www.tomscott.com/england/ 🟥 MORE FROM TOM: https://www.tomscott.com/ (you can find contact details and social links there too) ❓ LATERAL, free weekly podcast: https://lateralcast.com/    / lateralcast   ➕ TOM SCOTT PLUS:    / tomscottplus   👥 THE TECHNICAL DIFFICULTIES:    / techdif   Written and presented by Tom Scott Producers for Penny4 https://penny4.co.uk/ Cambria Bailey-Jones Guy Larsen Studio Associate Producer Heloise Lowenthal Studio Director of Photography Jamie MacLeod Studio Gaffer Frank Hammond Head of Post for Breadbox Studios https://www.breadboxstudios.co.uk/ Mandy Celine Associate Post Producer Isla McTear Senior Editor Jamie MacLeod Assistant Editor Alex “J’Rassic” Bate Sound Supervisor Dan Pugsley Sound Assistant Maggy Apodaca Subtitles by So Speedy https://www.sospeedy.co.uk/ With thanks to the Historic County Borders Project https://www.county-borders.co.uk/ Map data © OpenStreetMap contributors https://osm.org/copyright Select imagery/video supplied by Getty Images Executive Producer Tom Scott © Pad 26 Limited MMXXVI