Will Marlborough get a partial 20mph speed limit?

Written by Tony Millett on .

Following an assessment by Wiltshire Council of the viability of introducing 20mph speed restrictions in Marlborough, the debate on the results is just beginning. 


The report on the twenty-one 'Metrocounts' - or speed recorders - that counted traffic flow and speeds during the last week of September 2017, has been discussed at the Marlborough Community Area Transport Group (CATG) and will be discussed at next week's full meeting of the Town Council.

The CATG is closed to the press - so this article is based on the report itself.  The report was mentioned briefly at the last Town Council planning committee meeting, with full discussion deferred and with the possibility of a public meeting on the issue to be considered.

Wiltshire Council's report raises as many questions as it answers.  It does, however,  come up with three options - see below.

The report opens with this warning: "It is important to remember that all speed limits should be set where it can be expected that overall compliance with the limit can be realistically achieved."  20mph restrictions can only be introduced where the mean speed is at or below 24mph.

It may seem counter-intuitive, but if traffic is moving at an average speed of 24-30mph in a busy built-up area, you cannot reduce that speed by introducing a 20mph speed limit.  You have to apply other measures first. 

To confuse us a tad more, there are two kinds of 20mph restrictions - the 20mph Zones (where there will be traffic calming measures like road humps, raised junctions, 'build outs', chicanes and pinch points - to ensure speed are kept at or below 20mph).  And secondly, the 20mph Speed Limit area which only uses 20mph signs.

Note, however, that traffic calming cannot be installed on class A roads - such as the A4 and A346.  It seems the central parking along the A4/High Street does not count as traffic calming.

The 'Metrocount' data on volumes of traffic resulted in some fairly unsurprising figures - though it is good to have figures to back up perceptions. 

Far and away the highest figure recorded by the Metrocounts scheme was in London Road - a whopping 6,364 vehicles a day along the part between Barn Street and the Salisbury Road. 

A daily average of over 4,000 vehicles was recorded in the north side of the High Street (4,067), Salisbury Road (4,017 at the north end and 4,422 at the south end), Barn Street (4,620), London Road (just west of the George Lane roundabouts - 4,041) and Port Hill (4,051). 

Amongst some surprisingly low numbers were the two Kingsbury Street Metrocounts - 1,523 & 1,639.

Speeds were measured under 'free flow' circumstances - so speeds during 'rush hours' (8-9am & 3-6pm) were not counted "...as volumes of traffic and instances of queuing during those periods are factors that do not realistically represent free flow conditions."  Readers may wonder whether 'free flow' could describe traffic conditions on most of Marlborough's roads over the past months.

The Wiltshire Council assessment finds that speeds were too high to qualify for 20mph treatments along the A4/Bath Road, Pewsey Road, George Lane and London Road (East and West counts - those east of the George Lane junction). 

The central areas of the town (High Street, New Road, London Road and Barn Street) all qualify for a 20mph speed limit. 

There is a 'but': "...however this [area] does include two A Class routes, whereby pedestrian activity should outweigh the need for vehicular movements in order for a 20mph speed limit to be implemented successfully."   Does that mean the High Street needs a pedestrian crossing?  Or...what?

If a 20mph limit was introduced it would be spread into adjacent residential streets: The Parade, Kelham Gardens, Silverless Street, Oxford Street, Rawlingswell Lane, Kennet Place, Angel Yard and Chantry Lane.  Though it might be very surprising to find anyone who has driven at more than 20mph along the short length of Chantry Lane.

There are other areas where the average speed is close to 24mph and road markings could be introduced to slow traffic speeds.

Could that lesser scheme be applied to the one glaring gap in all this: George Lane - where average speeds were recorded of 25.5mph and 27.9mph?   These seem remarkably high if you consider the effect of the existing speed reduction due to residents' on street parking at George Lane's west end and the public on-street parking opposite the car showrooms.

This is an especially sensitive street due to the new crossing point for children and parents walking to the new Marlborough St Mary's Primary School's western entrance.  When the Wiltshire Council assessment was mentioned at last week's Town Council Planning Meeting, the Town Mayor, Councillor Mervyn Hall, suggested the omission of George Lane might be appealed.

In fact there are two huge omissions from the assessment:  there is no substantive mention of road safety (except for recent Collision Data) and the need to make it a priority.  And there is no mention at all of emission levels and air quality, which is now - since central government passed this 'hot potato' on - a Wiltshire Council responsibility.

Wiltshire Council's three options:

"Option One: Implement a 20mph speed limit throughout the full qualifying areas of Marlborough, with the addition of 20mph carriageway roundels one St Martins and Kingsbury Street."

"Option Two: Implement a 20mph speed limit throughout the qualifying area only, excluding St Martins and Kingsbury Street."

"Option Three: Do nothing - Traffic travelling at free flow conditions along Marlborough High Street already travel at or very close to 20mph and the implementation of a 20mph limit would not create a change in vehicular speeds.  A 20mph speed limit would only contribute to the clutter of street furniture in the area (by way of signage required to implement a 20mph limit.)"

None of these options mentions air quality or the problems of primary school pupils crossing George Lane.