Details of A27 Falmer Interchange model assumptions and Brighton Liaison

rob shepherd made this Freedom of Information request to Highways England Company Limited

This request has been closed to new correspondence from the public body. Contact us if you think it ought be re-opened.

Highways England Company Limited did not have the information requested.

Dear Highways England Company Limited,

This is a request for information concerning planning and modelling the improvements to the A27 Falmer Interchange, including requesting details of relevant liaison with the neighbouring Highways Authority (Brighton & Hove City Council B&HCC).

HE's LinSig model work is summarised in B&HCC's City Plan's Strategic Transport Assessment (May 2013) for Site 1 on Pages 178/9.

(A) Was HE's modelling based on analysing just the peak hour(s) traffic or did it follow the DfT's guidelines for handling cumulative queue build up in highly congested junctions, as set out in DMRB V12 S2?

(B) If it followed the DfT's guidelines, what were the queue length values provided to LinSig or calculated by LinSig for the start of the peak hours?

Specifically the Eastbound offslip, Knights Gate Road and the B2123 S & N.

(C) The vehicles freed from the queues on the North Roundabout can exit North, East, South or West but will mainly exit South (B2123) or West (A27).

What assumptions were made in the model about the mix of this traffic flow, i.e. the % taking each exit?

(D) Was B&HCC explicitly advised about the additional peak time load this traffic will place on the B2123, specifically at Bexhill Road, the Woodingdean Junction, Steyning Road and Rottingdean junction?

If not, was this issue raised in normal liaison meetings, so B&HCC could make its own assessment?

HE were aware of B&HCC's planned "Lewes Road Improvements" which substantially reduce that road's capacity and displaces high volumes of peak traffic into Rottingdean Coastal and Woodingdean wards, as set out in the 2010 JMP study and raised as a concern in the May 2013 Strategic Transport Assessment.

(E) Were the values used in the LinSig Models, referred to in (B) and (C) above, based on the Traffic flows prior to these major changes or after these changes?

B&HCC say they made HE aware of concerns expressed by local residents, that the already serious blocking back of the B2123 queue towards the A27 (a composite queue of the traffic unable to reach Bexhill Road or Woodingdean Junction), would by Year 2019 regularly reach the A27 and negate the key modelling assumption that the B2123 exit flow (south) is unobstructed.

i.e. some of the value of the planned improvements could be negated.

(F) How was this information communicated to HE, what actions were taken as result and what conclusions resulted from any assessment of this threat to the SRN?

Yours faithfully,

rob shepherd

rob shepherd left an annotation ()

Concerns about Falmer Road queue Blocking Back over the A27 and negating the A27 improvements were raised Dec 2014, originally in connection with a specific TA. The concern that the extra Traffic from the east slip Road might have nowhere to go .. and was not reflected in Woodingdean's loadings were raised shortly after.

HA did not respond to requests to clarify if they had used peak hour or 3-hour Modelling and B&HCC refused to say how they had informed HA of this concern.

This FoI is clarify this situation for number of local groups.

rob shepherd left an annotation ()

The junctions at Woodingdean and Rottingdean are notorious local bottlenecks. Long delays and queues of hundreds of cars are reported daily on local Traffic reports.

The scale of problem can be independently verified using Google's Historic Traffic data (which averages data over several months) or from TomTom's more detailed database.

Nevertheless, the local authority has not seemed concerned when Transport Assessments report these queues as 10-22 cars long and assess the impact of new housing as improbably low, using inaccurate congestion figures. It has also not reacted to other serious errors in Assessments, raising concern about the quality of checking.

These junctions are close to the county boundary and the Strategic Road Network, so they are affected by changes outside as well as inside the local authority's boundary, but the picture presented in Transport Assessments and in the City Plan is weak in assessing this.

All this has caused concern to several local residents groups, concerns that have resulted in numerous planning objections based on ignoring local congestion and pollution including the impact on public transport, petitions to the council and meetings between resident groups and council officials.

After some 18 months of trying to get to the bottom of these problems and feeling there has been little progress, a number of FoI requests have been submitted to obtain information about the traffic data and planning procedures and skills that inform our local Planning/Highways Authorities.

The aim is to establish an agreed base of facts that will make future communication more productive.

This is one of those FoI requests.

Beckley, Daniel, Highways England Company Limited

2 Attachments

Dear Mr Shepherd

 

Please find attached our response to you Freedom of Information request.

 

Kind Regards

 

Daniel Beckley, Team Executive, Area 4
Bridge House | 1 Walnut Tree Close | Guildford | GU1 4LZ

Tel: +44 (0) 300 470 1324

Web: [1]www.highways.gov.uk, [2]www.highwaysengland.co.uk
[3]Highways England

Registered in England and Wales No. 9346363

 

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Highways England Company Limited | Registered Office: Bridge House, 1
Walnut Tree Close, Guildford GU1 4LZ | Registered in England and Wales No.
9346363

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Dear Beckley, Daniel,

I am disappointed it took 21 days to say the requests should be referred elsewhere and that in at least one case this was inaccurate.

Request 6 was specifically about how HE / The Highways Agency was informed of residents concerns by B&HCC (as they say they did this).

This was specifically a question for you, not ESCC (who would not hold that information).

It reads

B&HCC say they made HE aware of concerns expressed by local
residents, that the already serious blocking back of the B2123
queue towards the A27 (a composite queue of the traffic unable to
reach Bexhill Road or Woodingdean Junction), would by Year 2019
regularly reach the A27 and negate the key modelling assumption
that the B2123 exit flow (south) is unobstructed.

i.e. some of the value of the planned improvements could be
negated.

(F) How was this information communicated to HE, what actions were
taken as result and what conclusions resulted from any assessment
of this threat to the SRN?

Yours sincerely,

rob shepherd

Ngobi, Diana, Highways England Company Limited

1 Attachment

Dear Mr Shepherd

 

Thank you for your follow up email of 23 November about modelling and
improvement works for the A27 at the Falmer interchange. I am sorry that
you were disappointed in our response.  After liaising with the local
authority I have provided some further detail below.

 

Your contextual comments and subsequent question F are repeated below for
ease of reference:-

“B&HCC say they made HE aware of concerns expressed by local residents,
that the already serious blocking back of the B2123 queue towards the A27
(a composite queue of the traffic unable to reach Bexhill Road or
Woodingdean Junction), would by Year 2019 regularly reach the A27 and
negate the key modelling assumption that the B2123 exit flow (south) is
unobstructed i.e. some of the value of the planned improvements could be
negated.”

“How was this information communicated to HE, what actions were taken as a
result and what conclusions resulted from any assessment of this threat to
the SRN?”

With regard to how “this information was communicated to HE”, I understand
you have now received copies of the relevant documentation from Andy
Renaut at B&HCC.

With regard to “actions”, we established with B&HCC that the Meadow Vale
development would have negligible increase of traffic affecting the Falmer
interchange.  The impact from Meadow Vale was 1 – 2 % of traffic flow and
is therefore within recognised traffic movement fluctuations.

With regard to the City Plan it recognises the need for a package of
improvements for the A27 junctions.

I can assure you that the safety of road users is of the utmost importance
to Highways England.  In the short term, therefore, on the east bound
approach to the Falmer interchange we have mitigated with signage and the
football club co-operates with the authorities in many respects including
the active encouragement of using public transport for the attendance of
matches.

Also we continue to work with East Sussex County Council, Brighton and
Hove City Council and Sussex Police, on the issue of traffic issues on the
A27 at Falmer that occur, in particular, at peak times because of the
southern dumb-bell roundabout configuration.

Concerns for any impact on the strategic road network from permitted and
proposed developments along the B2123 corridor, have been assessed and
have not been found to sufficiently add to the issues already under
consideration at the dumb-bell roundabout.

 

Yours sincerely

 

 

Martin Wright

Highways England | Bridge House | 1 Walnut Close | Guildford | GU1 4LZ

Tel: +44 (0) 300 470 1203

Web: [1]http://www.highways.gov.uk

 

Safe roads, reliable journeys, informed travellers

Highways Agency, an executive agency of the Department for Transport.

 

 

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