Just saw this morning the 20mph signs going onto the road surface - Honor Oak Road.

Research shows that signs alone do not have any influence on speed. It has been said that the 20mph zones also create a false sense of security for vulnerable and elderly/frail individuals.

The Government allowed Council's to implement these 20mph zones without any measure to enforce them i.e. additional funding for enforcement. Any one know how the Council/Police going to enforce this around the 20mph zones in SE23 ?.

They won't.

I would have thought initially most drivers would respond to the signs,
if only to cut their speed from a margin under 40mph to a margin under 30mph. But that is better than nothing.

Lewisham are not acting alone, as Southwark are making the change, Islington have made it, and 30Km/h limits are becoming common in residential areas in France, Germany, Belgium, Austria, Netherlands, Sweden, Norway and Switzerland.
This new limit is not going away.

Once the limit becomes more widespread, tfl need to run hard hitting tv/radio/newspaper campaigns to educate drivers why this is so important, just like the drink driving campaigns of the 70s.

Once public opinion is fully behind the new limit, the courts can hopefully take some measures to deter those who do not get the message.