BT Retail has issued a statement about congestion on its broadband network:
Broadband usage in the UK has been one of the great consumer technology success stories and we are aware that this accelerating demand has meant that a few exchanges can be congested at very busy times. The broadband team at BT Retail is working with our BT Wholesale colleagues to resolve this issue as soon as possible.
In BT Retail we are currently conducting a programme that is already introducing extra bandwidth availability and we are also working with technology that further improves the way that broadband traffic is managed at peak times. Both of these initiatives will improve your experience and if you are amongst the small number of broadband users that have been experiencing slower speeds through congestion you should be noticing improvements shortly, if you're not doing so already.BT Retail Statement
Users on our BT Broadband forum have recently been expressing concerns over slow speeds. The traffic shaping which they are alluding to has been controversial in a number of ways when other providers have introduced stricter shaping policies, although the effect of these should help most average users have a better browsing experience.