Download - Session 33 Riekele de Boer
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Transportforum 2010IPL Air Quality Innovation ProgrammeAir Quality alongside motorways
Riekele de BoerCentre for Transport and Navigation
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Rijkswaterstaat
Rijkswaterstaat is the executive agency of the DutchMinistry of Transport, Public Works & Water Management
Mission statement of Rijkswaterstaat:• Keeping Dutch feet dry• Sufficient and clean water supply• Smooth and safe traffic on roads and waterways• Reliable and usable information.
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National Road Network
• 3.260 km motorways (64 national roads)• 710 km noise barriers• 2.533 viaducts, 715 bridges• 16 tunnels• 8 aqueducts• 7 ecoducts• 14.244 signposts• 7.137 km barriers
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Air Quality in the Netherlands
The problem
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Air Quality in the Netherlands
Exceedances:
• NO2
– along motorways– in major cities
• PM10
– in major cities– in centre and south
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Air Quality in the Netherlands
National Air Quality Cooperation Programme (NSL)
European, national AND local measures needed Cooperation Ministry VROM with other ministries,
provinces and municipalities
Aims:• Public health• Spatial projects• Comply with
European standards (‘derogation’)
Innovation Programme Air Quality (IPL)
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IPL Air Quality Innovation Programme
• 2005 – 2010• 20 Million €• 9 large scale field trials• 3500 meetings • 60.000 hours members IPL team
12 final reports with English summary
IPL
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IPL Air Quality Innovation Programme
Aim: identify, develop and test local measures that can contribute to improve air quality along motorways
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IPL Air Quality Innovation Programme
Partnerships
• Government: Ministry of Transport, Ministry of Environment, local authorities
• Private sector: consultants, contractors
• Knowledge institutes: national and international scientific community
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IPL
Six directions of potentially promising measures
• Canopies and air treatment• Dynamic traffic management• Roadside vegetation• Road cleaning• Catalytic Coating• Noise barriers
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IPLDirection 1: Canopies and air treatment
• Improving air-quality near highway’s in densely populated areas
• light-weight canopies • Requirements
– Structurally sound– Safe and sustainable
• High costs
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IPLDirection 1: Canopies and air treatment
• Air pollution near tunnels a potential bottleneck• Passive and active dispersion techniques• Passive techniques
– Smart canopies: emissions are diluted or diverted by enhanced natural ventilation, multiple ventilation slits or a stack
• Active techniques– Mechanical ventilation and in-stack air-treatment – High costs and large ecological footprint
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IPLDirection 1: Canopies and air treatment
• Electrostatic Concept: active air technique • Particulates > 10 nm are positively charged• Deposit on a grounded gauze• Test were conducted in the Thomassen Tunnel on the A15• Max 15% reduction in vehicle related particulates• After optimization a higher reduction efficiency is expected
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IPLDirection 2: Dynamic traffic management
• DTM: measure to improve traffic flow and reduces congestion and improves air quality as a favourable side effect
• DTM in the Netherlands• Dynamax: Optimizing traffic flow by Dynamic
maximum speed • Rerouting the heaviest polluters like lorry traffic• Forecasting conditions favouring bad air quality
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IPLDirection 2: Dynamic traffic management
• Dynamax test at the A1 (Bussum-Muiderberg)– Aim is to reduce annual average NO2 concentration– Continuous monitoring of the traffic intensity by
means of induction coils in the tarmac – Adaptation of the speed-limit to stay below the
congestion threshold intensity– Traffic information by means of VMS (Variable
Message Sign)
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IPLDirection 2: Dynamic traffic management
Empirical test at the A58 (Goirle-Tilburg)– Aim is to reduce the number of day’s the daily PM10 limit
is exceeded– KNMI warns when weather conditions favouring high
particulate concentrations are forecasted.– RWS reduces the speed-limit from 120 km/h to 80 km/h
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IPLDirection 3: Roadside vegetation
• The effect of vegetation on air quality is not completely clear.– Vegetation is clamed to reduce pollution levels due to
filtering action– Vegetation affects wind speed causing pollution
concentrations to increase
• To gain understanding in the effect of vegetation on air quality two flied trail were conducted– At the A50 near Vaassen a measurement campaign was
carried out on existing roadside vegetation– At the A50 near Valburg a measurement campaign was
carried out on specially planted vegetation
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IPLDirection 3: Roadside vegetation
• Flied trails– PM10 and NO2 meteorological parameters– Simultaneous measurements on patches with and without
vegetations to asses the vegetation effect– Type of vegetation, coniferous or deciduous
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IPLDirection 3: Roadside vegetation
• Results– Direct along side the motorway pollution levels increase
slightly– On moderate distances (50-100 m) a positive effect is
found • Conclusion
– Vegetation is an un-effective measure in order to meet the threshold levels according to the regulations
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IPLDirection 4: Road cleaning
• Road cleaning: a measure to prevent the resuspension and enhance deposition of dust by wetting the road surface
• International trails suggest that road cleaning has beneficial effect on PM10 levels.
• In the IPL program several trails and modifications of road cleaning are investigated– In Nijmegen the effect of wetting is studied in relation to
porous asphalt concrete (PAC) en dens asphalt concrete (DAC)
– On the A50 south of Apeldoorn 3 methods cleaning motorways are tested. 2 dry methods and 1 spaying wet road salt (CACl2)
– An extensive trail on the A73 near Malden applying wet CaCl2.
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IPLDirection 4: Road cleaning
• Wet cleaning of PAC in Nijmegen showed non significant positive effect compared to DAC (the observation period was short and the effect was small compared to the measurement errors)
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IPLDirection 4: Road cleaning
• CaCl2 spraying: – CaCl2 is used to extend the duration of the wetting effect
because it attracts and binds moisture. – Test on the A73 show that the wetting effect remains
more than 48 hours.– CACl2 spaying reduces the total PM10 concentration by
over 10% and the PM10 road contribution by 20% to 30%
y = 0.81x
-5
0
5
10
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-5 0 5 10 15
PM10-road contribution (m 1) [μg/m3]
PM
10-r
oad
co
ntr
ibu
tio
n (
m 2
) [μ
g/m
3]
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IPLDirection 5: Catalytic coating
• Laboratory test have show that TiO2 and clean stone convert NO and NO2 in aqueous nitrate.
• During IPL program field test are conducted to find out if noise barriers coated with TiO2 or made from clean stone show a higher NO2 reduction potential
• Field tests were conducted along the A1 at Teschuur and along the A28 in de “Proeftuin” at Putten
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IPLDirection 5: Catalytic coating
• Field test A1 at Teschuur– 4 panels with different TiO2 coating were tested
– No significant decrease of the NO2 concentrations were measured.
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IPLDirection 5: Catalytic coating
• Field test A28 at Putten– During a period of 3 months a noise barrier coated with
TiO2 and a porous noise barrier were tested
– No significant decrease of the NO2 levels were measured
• Explanation– Short contact time between exhaust gasses and barrier– Meteorological conditions, wind speed & direction– Low temperature, low radiation level, high humidity
• Conclusion– No evidence is found that coated noise barriers show an
improved performance towards the deduction of NO2
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IPLDirection 6: Noise barriers
• Along the A28 at Putten a Barrier test-site “De Proeftuin” was erected in 2007
• A 4 m noise barrier as reference and 8 other noise barriers were tested in periods of 3 months
• Amongst these were innovative designs and coated barriers.
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IPLDirection 6: Noise barriers
Arrangement of the test-site “De Proeftuin”
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IPLDirection 6: Noise barriers
Impression of the measurement equipment
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IPLDirection 6: Noise barriers
• Result – 4 m reference barrier
– Advanced barriers to improve contact time or turbulent mixing like the T-top, do not perform better than the reference barrier.
714NO2
34PM10
1320NOx
Average impact 28.5m [%]
Average impact 10m [%]
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IPLDirection 6: Noise barriers
Schematic situation
Wind direction
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IPLFacts and figures test site noise barriers
2 local authority 1 amenity area
0 complaints of citizens
1200 meters road made of chopped branches
23 entries for the competition
8 winners of the competition
1 Minister
9 barriers tested of which 6 from contractors 1 stone through the
glass screen
5 measurement rounds of 3 months each
918 meter of tested noise barrier
13 measurement set up
55 measuring instruments
5 drenched laptops
10 km cable
11000 watt
Many men with dog
11.000 measuring hours of which 1.750 useful measurements
4 damped ditches
700 filters
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Final Remarks
• IPL has yielded a vast amount of knowledge
• Many results are ready for use 12 final reports with English summary
• Some topics need further research
• IPL has ended work on air quality along motorways continues
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Final Remarks1: Content
• Big research effort on air quality and roads
• Large scale test sites
• High quality measurements and data-analysis
• PM10 difficult to measure
• Measurement vs. Modelling
• Lab-experiments vs. practical experiments
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Final Remarks1: Content
+Barriers
-Catalytic coatings
+Road surface
+/-Vegetation
+/-DTM
+Canopies and air treatment
Relevance of measures studied:
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Final Remarks2: procedures
• IPL: extra measures with limited effect (‘end of pipe’)
• Therefore, focus on source measuresand cooperation between governments
⇒ ‘IPL paradox’