The experience from Stockholm city road tax Christer Johansson Lars Burman Tage Jonson Bertil Forsberg Umeå university

Exceedances of the PM10 limit value City of Stockholm

PM10: Stockholm has highest levels in Europe?! PM10 90-percentil AirBase: >700 sites 19 countries CAFE-PM, 2003

Stockholm trial goals Number of vehicle passages to the inner city should decrease by 10%-15% (morning and evening rush hours) Traffic flows should improve People residing or staying in the inner city should experience improved environment Emissions of NOx, CO2 and PM should be reduced

Tax for driving in the inner city area 2 km 1 0

Toll stations TAXES

Evaluation steps Traffic change & emissions Air quality Environment quality standards 2006 Exposure & health effects Long term exposure if the trial is permanented Meteorology Air quality Calculations Measurements

Substantial decline in traffic -22 % = passages Inner city: 15 % less total vehicle kms Goal was achieved!

Increased traffic on highway connecting north – south & tunnel connecting east – west

Mean diurnal cycle in traffic flow with and without tax

Results – Emissions Decrease in city centre 2006: tonnes/ year % Nitrogen oxides, NOx45-8,5 Carbon monoxide, CO Particles, PM10 total21-13 ” wear particles19-13 ” exhaust particles1,8-12 Hydrocarbons, VOC ” benzene3,4-14 Carbon dioxide, CO Goal was achieved!

Better air quality – particles, PM10 ca 0,5 % increase Street level, city centre 4-8 % decrease Roof level, city centre ca 2 % decrease

Better air quality – exhaust particles Street level, city centre 5-10 % decrease Roof level, city centre 5-6 % decrease ca 1 % increase

Better air quality – nitrogen oxides, NOx Street level, city centre 5-10 % decrease ca 1 % increase Roof level, city centre ca 6 % decrease

Limit values for PM10 and NO2?

PM10 Comparison w EU-directive STILL EXCEEDED

NO2 Comparison w EU-directive STILL EXCEEDED

Exposure calculations Living address, 2003 »Daytime pop have minor impact on mortality effects 100 meter resolution (35x35 km area) As if permanent system Long term exposure - mortality

Small changes in population mean concentrations

Expected health effects Exposure- response relations Consistent ER factors for mortality: –Holland, New Zeeland, France: 12%, 13%, 14 % increase per 10 ug/m3 NO2 –Norway (Oslo) 8 % increased mortality per 10 ug/m3 NOx ACS

Long term mortality effects if Stockholm trials are permanented Reduced exposure based on population weighted decrease of NOx concentrations –Decrease of 0,23 ug/m3 –Expected to give 25 – 30 fewer premature deaths per year

Cost benefit surplus Cost: SEK 2.6 billion Annual surplus: SEK 760 million Shorter travel times (SEK 600 mill) Increased road safety (SEK 125 mill) Health & Environment (SEK 90 mill) Revenues (SEK 550 mill) 4 years payback time

Measurements –NO2 –NOx –PM10 Meteorol. Traffic Other –Studs –Road wetness

Not possible to measure impact of congestion charge on air quality

Lower PM10 due to meteorology

PM10 levels 2003, 2004, 2005, 2006

NOx levels 2003, 2004, 2005, 2006

NOx Measured local street contributions SVEAVÄGEN HORNSGATAN Extra dieselbuses TRAFIK

Big impact of congestion tax Compare with other measures Reducing studded tires from 70% to 60% –would give similar reduction in PM10 as congestion tax –But: Congestion tax also reduces ultrafine exhaust particles Increased petrol tax not as effective –Congestion tax reduces levels where most people are being exposed New western/eastern link –Similar reductions in exposure

Other measures Parking: higher fees/taxes/restrictions Possibly similar effects as congestion charge Environmental zone Mainly exhaust emissions PM10 still a problem Dust binding (spring) Local and short effect on high levels High PM10 lowered Studded tire restrictions No effect on exhaust particles PM10 could be met…

Conclusions Large traffic reduction Lower emissions Small effect on concentrations Expect big effect on health Cost-effective measure