The announcements are everywhere. Please, TfL urge. Please keep away from two of the busiest stations on the network. Please don't change at Bank/Monument. Please don't change trains here. Even though there's a huge great big intersection marked between Bank and Monument on every single London Underground map. Please go almost anywhere else and change there instead. Please stay away, and then we can repair our escalators in peace.
TfL have all sorts of travel advice for passengers whose journeys normally take them through B/M, some of which would take you miles and miles out of your way. Want to change to the DLR? Nah, please go to Stratford or Bow or Tower Hill instead. Want to change between the Central and Northern lines? Nah, Charing Cross is a much preferred option. Please plan ahead, TfL hope, and please plan to go very much elsewhere.
But is this nannyish redirection advice really necessary? Well, yes and no. The series of tunnels between Bank and Monument is a badly laid-out warren of narrow walkways and awkward level changes, constrained by local roads and awkwardly-placed bank vaults. Block off just one tunnel and the repercussions elsewhere can be serious. In this case there are two escalators out of action, both downward, both between the Central line and DLR platforms. Scurrying passengers are having to descend a very narrow stairway instead, which is proving fairly nightmarish in any kind of busy conditions. Let me show you on this map. The two out-of-commission escalators are between 5 and 6 and 8. [the full key to the map is back here]
It seems that TfL are once again writing their travel advice for a lowest common denominator audience. (See also "Don't use Covent Garden, get out a station early and walk") There is absolutely no reason to avoid the Bank/Monument interchange for the next couple of months, not point blank, not in its entirety. Changing between the Central and Waterloo & City lines isn't affected at all. Changing between the DLR and Northern lines is still a doddle, up/down a set of back stairs. Most other changes are perfectly OK too, as you can see from the map, because they go (or can go) nowhere near the offending escalators. During less busy periods, outside peak hours, even the narrow staircases are perfectly passable. At three o'clock on a Thursday afternoon, for example, or at any time over the weekend, there's absolutely no need to avoid 5 to 6 to 8 at all. Piece of cake.
And yet TfL still insist on warning everybody away, all the time, because giving more accurate advice might be confusing for stupid people. Stupid people can only cope with simple instructions, like "Stay away", rather than the more realistic "Avoid changing at Bank/Monument during peak hours if you're intending to get to or from the DLR platforms via the Bank side, and watch out because the Northern line platforms could get rather busy. Until March." Or even "If changing between Bank and Monument, why not exit the station and walk down the street instead." Actually, that's quite good advice even when the escalators are working. In the meantime, don't let an over-simplistic warning massage scare you away. Not all the time, anyway.