This is a copy of an email I sent to Louise Tyers, Scrutiny Officer LCC on 27th February 2014
On behalf of our residents association I would like to state our support for an introduction
of enforceable 20 mph speed limits on residential streets and town centres.
It's difficult to see what the downside is to this.
- There has been an argument put forward that because car engines run more economically at 30mph than 20mph, which at a steady speed is generally correct. However more fuel is used in accelerating to 30 mph than to 20 mph, so in normal use a car will always use more fuel to attain 30mph between junctionc/traffic lights than levelling off at 20mph.
- It might take a minute or two longer to complete a short journey across a neighbourhood, but are we so bad at time management that this issue can be a realistic objection to the many benefits of speed reduction?
The benefits are
- Safer roads, because coming to a dead stop from 20mph happens in approximately 3 car lengths, whereas it takes six car lengths to stop from 30mph
- A less intimidating environment for cyclists and pedestrians, encouraging sustainable travel.
- Lowering urban and residential speed limits to 20 mph has been found to decrease child pedestrian accidents by up to 70%(Transport Research Laboratory). In Portsmouth the 20mph limit on all residential roads has reduced casualties by 22%.
We realise that there will be costs attached to the introduction of such a policy in terms of signage and awareness raising, but we believe the public investment in controlling a 20mph urban speed limit will be repaid in healthier , happier and safer neighbourhoods .