Author: John Stewart

The Select Committee were right to call on the Department for Transport to come up new estimates of how many people would be impacted by a third runway using the most up-to-date contours.  At present, as I indicate below, it is very messy.

Contours

Contours are created by averaging the noise out over a 16 hour day.  Until very recently, the Government argued that the 57 decibel contour marked ‘the onset of community annoyance’.  Following the SONA report it commissioned from the CAA, this has been revised down to a 54 and 51 contour.  The Guardian report was based on the numbers in a 45 contour (which has not been used before and is lower than the WHO currently regards as problematic).

Percentage of population severely annoyed by aircraft noise

57 contour (approx 9 miles from Heathrow) 13%

54 contour (approx 13 miles)   9%

51 contour  (approx 17 miles)   7%

45 contour   (unknown, but probably over 25 miles) 2.5%

                            National Policy Statement 2017 

                                               (using the 54 decibel contour)

Without 3^rd runway With 3^rd runway Difference

2015 590,000

2030 560,000 650,000 + 92,700

2040 475,000 515,000 + 45,000

2050 430,000 475,000 + 45,000

The Transport Select Committee Report 2018 found thatif  the 51 decibel contour was used the total number of people in the noise annoyance footprint in 2030 with a third runway in place would be 1.15 million.

The Guardian article reflects the number of people who would be impacted with a 3^rd runway in place using a 45 decibel contour.  The number would be 2.2 million in 2050.  

The Department for Transport put out this statement yesterday to confirm it:  The figures referenced include everyone that will experience any change in noise level, including those below the Lowest Observed Adverse Effects Level of 51dB LAeq and even those below 45dB LAeq.  

What we lack are figures about how many people currently live within the 45 or 51 decibel contours or how many would in 2030 and 2050 if a 3^rd runway is not built.  This means no comparisons can be made.  Almost certainly, though, the numbers currently within a 45 decibel contour will be over 1.5 million. 

by John Stewart

It would be a pity if night trains in Europe disappeared.  It would reduce choice for travellers.  That is why the week of action starting today organised by Train Tracks Europe – https://back-on-track.eu/action-week-april-2018/ – is important.  The campaign seeks to preserve the remaining night trains and bring back many of those which have been withdrawn in recent years.

Night trains may not be everybody’s cup of tea – and in fact on one or two nobody got a cup of tea! – but I’ll miss them if they go.  And perhaps more to the point, they will reduce my options for getting across Europe and not just for going on holiday for attending business meetings.

In fact, I don’t think I’ve ever used them on holiday.  But that’s just because I’m a lazy holiday-maker.  If you can’t get a tiny bit of luxury, a comfortable bed in a nice hotel on holiday, when can you get it?  Out with campsites, back-to-nature, do-it-yourself hostels and anything with Airbnb in the title!

But I digress.  Night trains have worked for me when going to meetings and conferences in Europe.  Take Barcelona.  I was invited to speak at a mid-morning press conference by a group of residents living under the flight path to Barcelona airport.  Left London on Eurostar late afternoon, change in Paris; in Barcelona for breakfast.  Admittedly my hosts struggled to welcome me:  they were so unused to somebody arriving by train from London that they went to the wrong station!

Press conference, a long lingering Spanish lunch by the beach, a stroll down Las Ramblas, onto the night train, checked my emails in Paris back at my desk in London mid-morning.

But my overnight trip to Vienna beats that.  I made £5,000 whilst on the train.

by John Stewart

Twenty years ago I wouldn’t have been reading a blog on metrics; far less writing one.  I’m not sure I’d really have had much idea of what “metrics” were.

But having chaired HACAN for nearly 20 years I now know metrics matters a lot.  The way noise is measured and the assumptions behind when it becomes annoying are critical factors in the determining Government policy on noise.

The importance of getting metrics right was recognized by the Transport Select Committee in its recent report on the National Policy Statement.  In effect, it suggested the Department for Transport recalculate the number of people which could be impacted by a three runway Heathrow using the most up-to-date metrics.  If this was done it believed ‘an extra 539,327 people would be captured in the annoyance footprint; taking the total number of people in the noise annoyance footprint to over 1.15 million’.  This is considerably higher than either the DfT or Heathrow have acknowledged.

The importance metrics right is the also one of the key messages of the report HACAN published this week (in association with Plane Hell Action) which found that aircraft noise can be a problem over 20 miles from Heathrow – areas where the traditional metrics simply ignored:  http://hacan.org.uk/wp-content/uploads/2018/04/Corridors-of-Concentration-Report.pdf  

It needs to be acknowledged the real progress there has been in recent years in devising more realistic metrics.  Credit goes to campaigners who gave banged on about outdated metrics for nearly 20 years, the Airports Commission who came to the issue with fresh eyes, Heathrow who came to understand the need for change and to the Department for Transport which moved things forward significantly in its new airspace policy announced in autumn 2016.

Things are not yet perfect – which I’ll come to later in the blog – but we are in a different world from the dark days of two decades ago.  Then the 57 decibel contour was king.  If you were inside the contour, it was accepted you had a noise problem.  Outside of it, you didn’t really count.

So what was so magical about the 57 decibel contour?  It was constructed like this.  Over a 16 hour day, the number of aircraft passing over an area and the noise of each plane were noted.  The noise was then averaged out.  This was then turned into an annual average.  If the annual average was over 57 decibel, the area was within the 57 decibel contour.  

Why 57 decibels?  Because, at the time, this was the level at which the Government argued ‘the onset of community annoyance’ began.  Acousticians were careful to say that it was more subtle than that and that some people became annoyed at lower levels but, to all intents and purposes, the 57 decibel contour became the official cut-off point, used at public inquiries and in industry and government documents to illustrate the numbers impacted by individual airports.  Latterly, it made no sense.  Around Heathrow for example places like Putney and Fulham – both clearly heavily impacted by aircraft noise – were outside the contour.  

Things began to look up when, over a decade ago, the EU required member states to use a different metric known as 55Lden.  It argued that the ‘onset of community annoyance’ started at a lower level.  The difference in numbers impacted at Heathrow was huge:  over 725,000 using 55Lden compared with around 245,000 using 57LAeq. 

The Airports Commission under Sir Howard Davies, although criticized in other areas, moved the metrics debate forward significantly.  It suggested a range of metrics should be used included the ‘N’ metric.  Local communities often feel these are more meaningful to them than the average noise.  So, for example, N60 would indicate the number of flights over 60 decibels that went over an area in any given period.  Heathrow also began to move towards using a suite of metrics.

The culmination of this improved process was the Government’s Airspace Policy announced in autumn 2016.  It effectively ditched the 57LAeq contour and replaced it with the 54LAeq as point where ‘the onset of community annoyance’ starts.  But it went further.  On the basis of a report it had commissioned from the Civil Aviation Authority (CAA), the Department for Transport recognized that around 7% of people could be disturbed when the noise averages out at 51 decibels.  These are more meaningful metrics.  And not far from what the World Health Organisation recommends.

In geographical terms, it takes the annoyance boundary from about Barnes (57 contour) to Clapham (54 contour) to about the Southwark/Lewisham border (51 contour).  As the crow flies, Barnes in 9 miles from Heathrow, Clapham 14 miles and Nunhead (fairly close to the Southwark/Lewisham border), 19 miles.  Similar calculations can be done west of the airport.  

Accurate metrics matter because only when there is a clear idea of the numbers impacted by noise from an airport can realistic policies be put in place to deal with that noise.  Metrics can determine levels of compensation, whether efforts should be made to provide communities with relief and respite from the noise and, indeed, to assess the impact of any new runway.

Campaigners will be pressing for real action based on these more meaningful metrics.  We will also continue to press for still further improvements.  For example, the existing metrics do not reflect the actual noise impact in areas like Ealing or Teddington which only get planes (on easterly departures) about 30% of the year but, when they do, the impact is significant.  A metric that measures only the days areas are overflown would be more meaningful and needs to be added to the suite of metrics used.  This would also capture the problems experienced in places like Reading and Caverham which are currently a little outside the 51 decibel contour when measured over a year.  A metric also needs to be used which reflects the cumulative impact on areas which experience noise from two airports, such as Heathrow and London City.

The dark days when one outdated metric was relied upon do seem to be over.  But the light is not yet shining as brightly as it could be.  

by John Stewart