I emailed a link to yesterday's blog on the Upper Ground detour to Lambeth's Road Danger Reduction Manager, Norma Fender, and received the following detailed response:
Sorry you came across an unexpected diversion when you were cycling with a group of children recently.
There are currently major works on Upper Ground behind the Royal National Theatre, accommodating 5 utilities plus Lambeth's own works, which has meant that we have had to authorise a road closure for all vehicular traffic (including cycles) from Cornwall Road to the up ramp to Waterloo road from 10.10.11 until 05.12.11. The road will have to be closed again for another period for more works in the new year.
The provision made for cyclists during these works is that they should dismount and walk their bikes on the footway past the works site for the short distance involved and then remount to continue their journey. At the moment there is no signage to this effect, but this signage (asking cyclists to dismount) will be installed, and this will make it much clearer to cyclists what is expected.
I'm sure you are aware that Lambeth is keen to promote considerate cycling on shared space for pedestrians and cyclists where appropriate (such as on the Thames path) but this is not always appropriate in places where there is a very high density of pedestrians, for example, the Vauxhall foot tunnel, where cyclists are also asked to dismount.
This is not the ideal situation for cyclists or pedestrians, however, major roadworks do require temporary road closures and diversions and less than ideal road situations until the works are completed.
It'll be interesting to see how the road works develop over the coming months and whether, for most of the time, there would be space for a cycle path, rather than a requirement for cyclists to dismount.