Traffic on a number of roads surrounding the central London charging zone has been monitored at the request of individual boroughs. [...] TfL has previously reported that the overall picture at these sites was of slowly declining traffic, and that there was no evidence from these data of significant adverse traffic impacts on local roads that might have resulted from charging. The indicators for 2006 continue this trend, with traffic levels on the whole noticeably down on pre-charging values in 2002. This mirrors the general background decline to traffic in central and inner London as highlighted elsewhere in this report.

And on Pages 264-265:

TfL has also made extensive provision for monitoring wider
traffic changes outside the immediate western extension zone.

TfL expected overall reductions in radial traffic in an ‘annulus’ surrounding the
extension zone, reflecting fewer trips being made to and from the extension zone. [...]

The picture here (Figure 14.16) is one of consistent reductions of between 6
and 7 percent [...] Emerging results from both of these indicators are consistent with the traffic changes observed in the extension zone itself and on the boundary route, and with TfL’s expectations for the scheme.

In other words, people's worries that their neighborhoods might become "rat runs" proved to be unfounded.

Well, not so good timing, actually, but I'm sure it's not easy to speed up the release of a 279-page document.