A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| ELR | Route | Section |
|---|---|---|
| DAC ℹ️ | Exeter and Devonport (or Devon and Cornwall) Line | Cowley Bridge Jn to St Budeaux Jn |
| DAE1 | Darlington and Eastgate-in-Weardale Line | former Parkgate Jn to former Shildon South Jn |
| DAE2 ℹ️ | Darlington and Eastgate-in-Weardale Line | former Shildon South Jn to former Wear Valley Jn |
| DAE3 ℹ️ | Darlington and Eastgate-in-Weardale Line | former Wear Valley Jn to Eastgate |
| DAN ℹ️ | Danygraig Branch | Burrows Jn to Danygraig |
| DAP | Barrow Avoiding Line | Dalton Jn to Park South Jn |
| DAT1 | Widnes Train Care Depot | Ditton Marsh [1] |
| DAT2 | Widnes Train Care Depot | Ditton Marsh [2] |
| DBP1 | Birmingham and Derby Line | London Road Jn to Kingsbury Jn |
| DBP2 | Kingsbury and Water Orton Line | Kingsbury Jn to Water Orton East Jn |
| DBP3 | Birmingham and Derby Line | Whitacre West Jn to Proof House Jn (via Water Orton) |
| DCF | Down Cambridge Flyover | Hitchin North Jn to Hitchin East Jn |
| DCL | Didcot and Chester Line | Didcot Parkway to former Handsworth Jn |
| DDB | Devonport Dockyard Branch | Keyham (or Dockyard) Jn to Devonport Dockyard |
| DDY ℹ️ | Doncaster Down Yard | Decoy North Jn (excl.) to Bridge Jn (excl.) |
| DEC | Didcot East Curve | Didcot East Jn to Didcot North Jn (via Avoiding Line) |
| DEX ℹ️ | Derbyshire Extension Branch | Rectory Jn to Gedling Colliery |
| DFN ℹ️ | Dufftown Branch | Keith Jn to NR boundary |
| DHF | Denbigh Hall Flyover | Denbigh Hall South Jn to Flyover Summit Jn |
| DJH | North Lancashire Line | Daisyfield Jn to Hellifield South Jn |
| DJO1 | Oldham, Ashton, and Guide Bridge Line | Denton Jn to Crowthorne Jn |
| DJO2 ℹ️ | Oldham, Ashton, and Guide Bridge Line | Crowthorne Jn to former Ashton Moss South Jn |
| DJP | Cambrian Coast Line | Dovey Jn to Pwllheli |
| DJW | Wirksworth Branch | Duffield Jn to Ravenstor |
| DLO ℹ️ | Darnall East Curve | former Darnall West Jn former Attercliffe Jn (excl.) |
| DLS ℹ️ | Duddeston Jn to Birmingham Freightliner Terminal | |
| DMY ℹ️ | Winchburgh Loop | Winchburgh Jn to Dalmeny Jn |
| DOC | King’s Lynn Dock Line | King’s Lynn Dock Jn to King’s Lynn Docks |
| DOL1 ℹ️ | Doncaster and Leeds Line | Marshgate Jn (Doncaster) to Wakefield Westgate South Jn (excl.) |
| DOL2 ℹ️ | Doncaster and Leeds Line | Wakefield Westgate South Jn to Leeds |
| DOL4 ℹ️ | Doncaster and Leeds Line | former Gelderd Road Jn to Leeds |
| DOW | Doncaster to Wrawby Line | Marshgate Jn to Wrawby Jn |
| DPJ ℹ️ | former Dudley Jn to Walsall, Pleck Jn | |
| DPS ℹ️ | Didcot Power Station | |
| DRA1 | Drax Power Station | Approach Tracks (Drax Branch Jn to Power Station Jn) |
| DRA2 | Drax Power Station | Merry-Go-Round Loop |
| DRS1 ℹ️ | Dewsbury Goods Branch | Dewsbury East Jn to COM |
| DRS2 | Dewsbury Goods Branch | COM to former former Headfield Jn |
| DRS3 ℹ️ | Dewsbury Goods Branch | former Headfield Jn to former Dewsbury Jn (excl.) |
| DSD ℹ️ | Dinting Chord | Dinting South Jn to Dinting East Jn |
| DSE | Liverpool and Manchester Exchange Line | Edge Hill East Jn to Deal Street Jn |
| DSN1 | Darlington and Saltburn (or Tees Valley) Line | Darlington South Jn to Eaglescliffe South Jn |
| DSN2 | Darlington and Saltburn (or Tees Valley) Line | Stockton Cut Jn to Redcar COM (Coatham Bridge) |
| DSN3 | Darlington and Saltburn (or Tees Valley) Line | Redcar COM (Coatham Bridge) to Saltburn |
| DSS | Euston Carriage Depot | Down side |
| DSY | Westbury Sidings Yard | Down side |
| DUY | Doncaster Up Yard | Potteric Carr Jn to Bridge Jn |
| DWC | Didcot West Curve | Didcot West Curve Jn to Foxhall Jn |
| DWS | Hope Valley Line | Dore West Jn to Dore Station Jn |
| DWW1 | former Dalston Western Jn to Stratford | former Dalston Western Jn to Navarino Road Jn |
| DWW2 | former Dalston Western Jn to Stratford | Navarino Road Jn to Stratford |
| DWY | Doncaster Wood Yard Sidings |