Reducing congestion essential to help buses meet EU NOX targets

Tailpipe data firm Emission Analytics has issued a warning to bus and vehicle fleet owners planning to retrofit their vehicles with nitrogen oxide (NOX) reducing equipment, as stringent real-world analysis is need to ensure they meet the EU emission targets. The firm says the Department for Transport (DfT) support for local authorities with up to £500,000 of funding from its £5 million Clean Vehicle Technology Fund is a positive step. However, the methods by which it monitors the NOX produced needs to be
August 15, 2014 Read time: 3 mins

Tailpipe data firm Emission Analytics has issued a warning to bus and vehicle fleet owners planning to retrofit their vehicles with nitrogen oxide (NOX) reducing equipment, as stringent real-world analysis is need to ensure they meet the EU emission targets.

The firm says the 1837 Department for Transport (DfT) support for local authorities with up to £500,000 of funding from its £5 million Clean Vehicle Technology Fund is a positive step. However, the methods by which it monitors the NOX produced needs to be robust as the exhaust output suggested may not be close to the real-world figures.

Emission Analytics calculates that there is around a 22 per cent discrepancy on average between the estimated emissions and the real-world figures. Emission Analytics added that this disparity increases if roadside gas analysers are used, as they only record the ambient pollution. This means that local authorities could be inadvertently spending money on vehicles that fail to produce lower emissions.

CEO Nick Molden said, “Choosing a vehicle on the basis of its theoretical emissions, without understanding how it operates in the real world is a lottery. It is quite possible to select a vehicle that theoretically will help reduce NOX emissions, only to find that it has a negative impact.”

The study that Emission Analytics carried out, with 500 Imperial College London, showed correlation between lower speeds and more NOX being produced, and shorter bursts of acceleration also contributed. It adds that analysis of a light Euro-5 diesel engine showed that its real figures produced more than three times the Euro-5 threshold.

However, Eminox, which manufactures exhaust emission control systems for heavy-duty diesel vehicles, believes this may not be the case, as research carried out by King’s College London showed positive signs. Ninety three London buses retrofitted with its selective catalytic reduction system helped reduce kerbside NOX pollution by 23 per cent on Putney High Street.

Eminox admits that these figures, which included a 12 per cent decrease of NO2, could be further increased if less congestion was present on the roads.

The study suggested that over its three month trial in 2013, the results conclusively show that retrofitted SCR systems had helped to lower the NOX and NO2 levels, and could support delivery of the EU’s limit value threshold.

Air Quality & Weather Systems

Related Content

  • July 20, 2015
    New report indicates reduction in London’s pollution
    A new report, produced by experts at King's College London, for the first time quantifies the health and economic effects of the air pollutant nitrogen dioxide (NO2), where all previous studies have focused on particulate matter (PM2.5). Combined together the effects of both pollutants reveal a higher health impact than previously estimated after taking into account this further pollutant. The study also found that nearly half the health impacts are caused by air pollution outside London such as diesel
    Read More
  • June 29, 2016
    Are truck bans the wrong move in the battle for air quality
    Low emission zones and heavy goods vehicles’ access to city centres may at first glance appear attractive but how effective are such controls? Jon Masters reviews emerging trends across Europe. Around 1,700 European cities have implemented low emission zones (LEZs) and in addition some have restricted city centre access for heavy goods vehicles (HGVs). Even those that restrict HGV access, such as Paris and Rome, allow exemptions at certain times and for particular classes of vehicle. But with what effect?
    Read More
  • April 26, 2019
    London debuts three more low-emission bus zones
    Transport for London (TfL) and the city’s mayor Sadiq Khan have introduced three more low-emission bus zones (LEBZ) to help reduce toxic air in the UK capital. There are now 10 LEBZs in London, which are expected to reduce nitrogen oxide (NOx) by 90% along some of the capital’s most polluted roads. Buses operating within the zones meet the cleanest emissions standards and have been delivered through a combination of new and retrofitted vehicles, TfL says. The three new zones in Lewisham, Stratford and
    Read More
  • December 1, 2015
    VW scandal prompts emissions testing debate
    In the wake of the VW scandal John Kendall looks at emissions testing on both sides of the Atlantic. Since the VW emissions story broke in September, emissions testing has come under greater scrutiny, and none more so than in Europe, where critics have long been highlighting the weaknesses of the testing system. Ironically, changes to the emissions testing process were already under review but the story has pushed it up the agenda.
    Read More

Highlighted Content