Monday, 4 February 2013

The debate on speed limits begins

Later this year the Council is due to decide on whether to extend the 20 mph speed limit which is currently being piloted in south Edinburgh.  

The council is also about to consult on whether to extend the 20mph speed limit throughout most parts  Edinburgh.

Now the Edinburgh Centre for Carbon Innovation (currently based in South College Street), has commissioned research which suggests that reducing speed limits leads to more air pollution.  The research is reported in this report in The Scotsman.
"The TRL report said cutting speeds below 40mph was likely to increase pollution, such as nitrogen oxides and particulates. Carbon dioxide emissions would also go up.
This is because of the increased amount of acceleration and braking in stop-start driving, although these could be reduced if traffic flow was smoothed. The report said 40mph was the optimum speed for minimising vehicle emissions and pollution.
The report found reducing speed limits alone usually cut average speeds by only one quarter of the change in the limit."
All fuel for the local debate on whether to make the pilot permanent.

4 comments:

Anonymous said...

Not to mention evidence from Portsmouth suggesting that blanket 20mph limits have increased the danger.

The road traffic incident data that CEC used to justify the pilot here didn't stand up to scrunity. There was no data at all on the speed for one thing (one incident even involved a stationary car!)

The money wasted on blanet 20mph signs would've been better targetted at two areas (Melville Terrace and Priestfield) where the VSI occurred and where poor road design was an aggravating factor.

Just another in a long line of terrible transport decisions by CEC.

Cameron Rose said...

Noted, thanks.

Anonymous said...

may be a small pratical problem when enetering a 20mph area.When raining and in the dark,signs no too obvious when other vehicles-buses and large lorries on the adjacent road.As reported sides can be driven along at any speed;eg., Gordon terrace as just one,oh and Lygon Road too. Monitoring a wee difficulty.
Tom

Cameron said...

Tom,
Noted, thanks.
C.