Low Emission Zones (LEZ)

Low-emission zones (LEZ) are gaining traction in major cities across Europe. The driving force behind LEZs is human health.

The European Commission estimates that air pollution is responsible for over 300,000 deaths in Europe each year, more than caused by road accidents. Furthermore, the estimated human health cost to the European economy attributed to air pollution is between 427-760 billion Euros per year. The European Union set ambient air quality standards mandating maximum permissible level of pollutants in the air and in an effort to tackle transports contribution to air pollution. Ever-tougher regulated emission levels are in place to be applied to new vehicles. However, ambient air quality standards can be exceeded in areas of high vehicle density, leading to local “hot spots” of air pollution. It is in these regions where the introduction of low-emission zones can significantly improve air quality. Therefore, as of spring 2008, there are currently 54 active and planned LEZs across Europe. One of the largest is the London LEZ, covering most of Greater London (approximately 1600 km2). CDTi is one of the top providers of particulate matter emissions reduction systems to vehicles operating in the London LEZ.

CDTi’s patented solutions for low-emission zones target existing vehicles on the road and include the following verified solutions:

  • Purifier™ e4, based on a wall flow diesel particulate filter for maximum performance, to bring vehicles up to the Euro 4/EPA Level 3 standards
  • Purifier™ e3, based on a partial filter, enables lower levels of emissions reduction where cost or operational limitations restrict the applicability of full diesel particulate filters. In the US, these solutions have shown particular success where exhaust temperature profiles are too low for proper operation of a DPF, and they also offer the Best Available Control Technology (BACT). Purifier e3 brings Euro 2 vehicles up to the Euro 3/EPA Level 2 standards

Relative to traditional DPFs and DOCs, the Purifier family is unique in providing reductions in PM while actually decreasing overall NOx levels, with no increase in NO2. This makes CDTi's Purifier systems especially attractive for LEZ areas with NO2 or NOx sensitivities. For example, NO2 neutrality is a requirement for inclusion in the Scottish Emissions Reduction Register. 

Another key distinction of the Purifier systems is that they are the only verified PM solution that also lowers CO2 emissions and provides fuel economy. This becomes increasingly important as carbon emissions fall under more scrutiny, including talk of mandatory carbon footprint reporting and the potential of carbon regulations extending to the transportation sector.