Planning Permission Must be Withheld from this Uncontrolled Crossing on Sherborne Rd South With Hopelessly Inadequate Visibility

Planning Permission Must be Withheld from this Uncontrolled Crossing on Sherborne Rd South With Hopelessly Inadequate Visibility

Approaching Traffic from the A259 will have Inadequate Visibility of the Proposed Uncontrolled Crossing!

The A259 is busy a trunk road and the proposed WoC uncontrolled crossing will be situated on a blind limb of the roundabout where Sherborne road joins the A259.

The design has previously failed a safety audit over identical concerns.

All that is proposed as a solution is to temporarily cut a few trees trees while ignoring all other relevant DfT guidance on highway visibility requirements at crossings

The safety issue is illustrated by the following diagram.

The National Speed Limit applies to the section of A259 shown to the bottom left and to the roundabout.

Cars approaching the crossing will arriving from outside the 20 Mph speed-limit that is proposed to start only at the very edge of the crossing itself and then extend northwards.

DFT Traffic Signs Manual Volume 6 section 15.5 (Visibility) contains the following advice:

15.5.1. Minimum distances for visibility of crossings for approaching traffic are set out in Table 15‑1. For more detail see 2.1.5.
Table 15‑1 Recommended visibility distances for pedestrian crossings

DfT speed and Distance table

DFT Traffic Signs Manual Volume 6 section 13.4 (Traffic survey) gives the following advice on recording 85th percentile speed:

13.4.3. Vehicle speeds should be recorded at peak and off‑peak periods. The measured speed of vehicles in each direction, taken roughly 50 m before the crossing site, should be recorded and the highest 85th percentile speed used in the assessment. The speed limit should also be noted.

ChiCycle can find no documented traffic speed survey assessments relating to this proposed uncontrolled crossing.

ChiCycle understand the adjacent roundabout and A259 dual-carriageway section shown are currently national speed limit zones.

The A259 approach to the crossing within 50 metres from the East is highly likely have an 85th percentile speed well in excess of 30 mph.

It is eminently realistic to expect a properly conducted Traffic Survey to record higher 85th percentile speeds above 40Mph (Requiring an 80 metre visibility splay for adequate visibility) !

A proper Traffic Survey (as recommended by DfT design guidance) is necessary to design any DfT standards complaint crossing in this location.

Planning permission must be withheld until full and adequate justification is given why such an extremely limited degree of visibility is provided for Eastbound drivers on the A27 as they approach this crossing!

Latest Plans Show the Crossing will have Hopelessly Inadequate Visibility

A screen clip of the latest drawing (shown below) shows inter-visibility is intended only to be an entirely inadequate 25 metres!


The proposed 25 metre inter-visibility distance is only 62% of DfT Table 15‑1 recommended visibility distances where the visibility splays reach into a 30 Mph zone! However, the visibility splay in this case reaches into a national speed limit area demanding far greater visibility at the crossing.

Are developers really expecting our community and council to believe (without evidence) the highest 85th percentile speed on the A259 (including a dual carriageway section with national speed limit) is 20 Mph? This is an incredible assumption to expect us to swallow!

Even the Claimed Provision of the Entirely Inadequate 25 metre Inter-visibility Splay looks Highly Questionable and Unlikely to be Delivered in Practice!

The DfT Manual for Streets (MfS) gives advice on visibility requirements for inter-visibility.

MfS Figure 7.17 shows the required vertical visibility envelope (shown Below)

The following photograph was taken on the 9th April 2023 from the A259 carriageway with the centre of the camera lens precisely 1050mm above the surface of the carriageway (DfT presumed eye height of a car driver). 

As can clearly be seen, there is a crash barrier installed at approximately the same height as a typical car drivers sight line of the crossing.

Will it really be possible to see a 600mm tall child on the proposed crossing from this vantage point?

It can also be seen that the area behind the barrier is wild and that it has apparently not been adopted by the local highway authority as a regularly mown area where visibility of the more favourably positioned existing uncontrolled crossing is maintained.

View of crossing area from 1050mm above the road surface
The view (or indeed the absence of a view) of the proposed uncontrolled crossing area from 1050mm above the A259 road surface

The image shown above raises serious questions over how visibility of the proposed crossing will be achieved and maintained:

  1. If only a 24 metre inter-visibility distance is to be provided (suitable only if A259 traffic has its 85th% maximum speed maintained below 20 Mph), then what traffic calming systems are to be installed on the A259 and its roundabout to ensure motor vehicle speeds cannot exceed this low 20Mph speed (this is an exceeding low speed considering this section of A259 is a dual carriageway)?
  2. Is it realistic to enforce a 20mph speed limit on this section of the A259? The 20Mph limit on local residential streets is poorly adhered to and enforced. It is difficult to imaging 20 Mph zone could be adequately implemented on this section of the A259!
  3. What plans are there to remove the crash barrier and/or grade the surrounding road/landscape so that the crossing is made visible from drivers eye height?
  4. What will be the extent of the tree felling to improve visibility?
  5. What measures will be put in place to ensure trees and/or scrub does not re-grow within the sight line of this inter-visibility area?
  6. What plans are in place fro WSCC to adopt the land so it is possible for them to maintain continued clear visibility between cars drivers and the uncontrolled crossing?
  7. What maintenance schedule is proposed for either WSCC or contractors to regularly mow this critical inter-visibility area so tall grass and weeds do not grow up obscuring line of sight to the crossing?

The proposed drawings shows an area with two small green inter-meshing circles labelled “Extents of existing landscaping to be removed to facilitate 25m visibility splay”.

ChiCycle note this area does not cover the entire length of the visibility splay.

Considering 25 metres is already a hopelessly inadequate visibility splay for this crossing, half hearted pruning made in an ill defined area in the middle of this thicket is an unrealistic way to ensure long term inter-visibility at this crossing.

ChiCycle will Hold WSCC Council Highways Officers Personally Responsible for Inevitable Traffic Accidents if they Advise Visibility is Acceptable at this Blind Uncontrolled Crossing

DfT National Guidelines make it crystal clear that 25 metres forward visibility is woefully inadequate for this crossing that has vehicles approaching from a section of national speed limit dual carriageway. What is being proposed would remain entirely unsuitable even if the A259 was a quiet B road with a 30 Mph limit. That scenario would still require at least 40 metres visibility of the uncontrolled crossing.

Sadly, ChiCycle anticipate WSCC Highways Officers will nonetheless falsely advise councillors the scheme fully complies with DfT guidelines.

WSCC Highways Officers have an unenviable record advising on active travel and safety:

Unfortunately, it appears inevitable WSCC Highways Officers will once again fail to act professionally and will falsely claim this blind uncontrolled crossing has adequate indivisibility and is compliant with DfT standards.

Presumably, there is strong political motivation to permit unlimited construction of new houses while avoiding taking responsible town planning decisions.

It is a shame our local authority is not working in the interest of its residents while also choosing to mislead us about the schemes compliance with DfT guidelines.

When the inevitable road traffic accidents occur at this unsafe crossing, the ChiCycle team will do our best to see those responsible for giving poor advice will face custodial sentences.



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