If your conference runs over the allotted time span and you are forced to travel in central London in the early hours of the morning you can take heart from news that from 12 September 2015 Transport for London (TfL) are launching their Night Tube service.
This is a round-the-clock service on sections of the London Tube network on Fridays and Saturdays.
The Night Tube service will operate on five lines: the Jubilee, Victoria, and most of the Central, Northern and Piccadilly lines with trains running around every ten minutes throughout central London but dropping to around every 20 minutes further out of town.
TfL also plan to expand the night time service to parts of the Metropolitan, Circle, District and Hammersmith & City lines once their modernisation programmes are complete.
Fares will be charged at standard off-peak rates for travelling on the Night Tube.