Given the NR planners usually give cross London times as part of a journey into then out of London, they will also need to contain a rough guide of how long it will take for you to get from the main station to the tube station (this might be longer than the usual transfer time) as well as how long you are likely to spend waiting for a train.
I agree 100%. All the London terminals have a very large minimum connection time, which I believe is specified as such exactly for this reason. London Bridge is 10 minutes, and Paddington 15 minutes. This is added to the inter-station transfer time when planning a journey.
If the planner got you into London Bridge then gave you a train out of Paddington 20 minutes later, there's not a chance in hell you'd make that.
Agreed, but that's not how it works. In reality you have the London Bridge connection time (10 mins) + transfer time (30 mins) + Paddington connection time (15 mins) = a total of 55 minutes allowed between your train arriving in London Bridge and your train departing from Paddington. This is what the journey planners allow.
It is excessively long, hence almost all options route you via Charing Cross (and thence with the Bakerloo line direct to Paddington - shown as a much more realistic 18 minutes in the ATOC data) instead. It is a journey I have to make every few months or so and I used to believe the journey planners and go via Charing Cross. But I have recently realised it is quicker to change to the Jubilee line at London Bridge.
