(Please see comments below article for updates and further clarification – 18th Oct 2011)
On Wednesday evening we held a meeting for Langham Road residents who had concerns regarding the bend on Langham Road. We had a brilliant turn out, from both residents new to the process and old hands, and were able to discuss a range of issues. We had some very positive debates and many good points came out during the evening. We discussed a variety of options to potentially further slow traffic on the bend, including painting a pattern on the road using anti-skid paint, providing ‘passing place’ bays on either side of the road, installing a flashing ’30mph’ sign, installing an additional raised table, a block work strip, or writing slow across the road.
As became apparent on Wednesday night, and throughout the whole process, we are constrained by the different wants, needs, and priorities of residents. We also have a limited budget, which we have already stretched to the absolute maximum. As the design currently stands – and has been discussed in depth over the past few months – we expect traffic speed to be satisfactorily reduced on the bend in Langham Road due to the variety of measures proposed. In particular, the two raised tables that sit either side of the bend, which will reduce speed in the approach to the bend.
Average speeds down Langham Road have been recorded at 32mph. By using a formula in Manual for Streets (published by the Chartered Institution of Highways and Transportation) it is possible to ascertain speed reduction resulting from a bend in the road. Based on the bend radius on Langham Road it can be worked out that there is an approximate 4mph speed reduction. Therefore, as discussed last night, the bend itself reduces the speed of vehicles.
The Department for Transport (DofT) has released road traffic guidance on traffic calming. Their studies have shown that where raised tables/flat top/bump speed features have been installed average vehicle flow reductions of 20% can be expected. The Department for Transport has also studied the impact of raised tables/flat top/bump speed features when placed at various distances. Along Langham Road the features are placed on the designs between 60m-100m apart. The DofT’s findings show that we can expect the following:
For features 100m apart the average speed of vehicles traveling between the two points will drop from 30mph average speed to 22mph.
For features 60m apart the average speed of vehicles traveling between the two points will drop from 30mph average speed to 19mph.
Therefore, when taking into account the speed reduction imposed by the radius of the bend itself (4mph) and the expected reduction of average vehicle speed in the approach to the bend, from both directions, we expect that traffic speed will be considerably reduced on the bend.
The various suggestions discussed on Wednesday evening may or may not have a further impact on the speed of vehicles. Residents vary in their enthusiasm for loosing parking to facilitate ‘passing places’, for the application of large ‘slow’ signs painted on the road, and anti-skid paint which has a limited lifetime. At this late stage of the design process, where the budget has been filled and indeed already stretched, we cannot afford to install an additional feature on Langham Road – which does already have six features along its length and the project as a whole must be taken into consideration. Furthermore, taking into account the above statistics, we believe the current design will prove effective in slowing traffic on Langham Road, including on the bend itself.
Therefore, we propose to move ahead with a suggestion mentioned during the Wednesday meeting – to leave the designs as they are and for residents to monitor the success of the project upon completion. Over the months following construction residents are best placed to judge the effectiveness and whether further remedies are required. This is an integral part of the DIY Streets process and we will be providing residents with the necessary information and guidance in the coming months.
Residents who live on the bend will establish a dialogue for the future with Haringey Council by submitting a letter informing them that they will monitor the success of the project on the Langham bend in the months following completion.
The letter will be sent to:
London Borough of Haringey
2nd Floor South, River Park House
225 High Road
London, N22 8HQ