The London Borough of Ealing is proposing a wide area 20 mph speed limit in Acton. You can read more about it and respond to the consultation (which ends on the 18th December so you need to get your comments in quickly) here: http://www.ealing.gov.uk/info/200628/current_consultations/2059/acton_20_mph_speed_limit_trial_consultation
This is a “trial” scheme, but if successful is likely to be rolled out across all of the borough. From past experience such trial schemes are rarely rolled back simply because of the money spent on implementing them.
The Alliance of British Drivers has consistently opposed wide area 20 mph schemes because there is no evidence of road safety benefits. In fact the council are pre-empting a study which has been commissioned by the DfT on such schemes, but evidence from existing ones make any benefits appear to be very unlikely. Indeed in some schemes, accidents have increased. Although traffic speeds may be reduced by 1 mph (on average) in such schemes, that is hardly noticeable by most people.
But it can add significantly to journey times and put you at risk of collecting a speeding fine for driving at what you might consider a safe speed. The council’s supportive arguments are full of dubious claims, such as that it will reduce traffic congestion – that is simply nonsense as there is no evidence whatsoever to support that. Likewise they say lower speed limits will encourage cycling and walking, which might be beneficial if it was true, but again there is no evidence of such effects in existing schemes.
The council does not tell you what this scheme will cost in the consultation material, but it will be expensive. And it will be a waste of money that would be better spent on other road safety projects.
So please make sure you object if you live in the borough, or drive through it.