Mayor of London announces intended changes to the LEZ program

13 February 2013

The Mayor of London, Boris Johnson, has announced intended changes to the London Low Emission Zone (LEZ) program. The phase five of the program would focus on the city bus fleet, while commercial vehicles such as heavy trucks, buses and coaches—originally planned to be affected—will not be included in the program. Exempting commercial vehicles will save £350m in compliance costs.

A number of new, still unspecified measures will be introduced to ensure continuing air quality benefit, in spite of the exclusion of commercial vehicles from the program. The new regulatory package, named “Ultra Low Emission Zone”, would in fact double the air quality benefit originally predicted under phase 5 of the LEZ regulation, according to the Mayor. The ultra low emission zone, considered for introduction from 2020, would aim to ensure all vehicles driving in the city center during working hours would be zero or low emission. It will be interesting to see how this ambitious objective will be achieved, especially if commercial vehicles are not included in the program.

Phase 5 of the London Low Emission Zone is due to be introduced in 2015. The Mayor has confirmed it will now only apply to Transport for London’s (TfL) fleet of buses. By limiting phase 5 of the Low Emission Zone to the TfL bus fleet the Mayor expects to save around £350m in costs for businesses using vehicles that would have been affected by the changes.

In a speech at City Hall, the Mayor explained how he believes a range of alternative measures can deliver around 200% of the benefits forecast by the original proposal for phase 5 of the Low Emission Zone. Transport for London will begin work on preparing options for a public consultation on the new program.

A key reason for proposing the changes is that “it has emerged that Euro vehicle standards have not actually reduced NOx emissions for vehicles operating in urban environments to the level that was forecast”. NO₂ levels would therefore not have been reduced as planned under the original proposals for phase 5.

Hybrid buses have been chosen as the central technology to achieve the emission reductions. The Mayor has already committed to deliver 600 new “Bus for London” vehicles, which alongside a new commitment to deliver another 600 ‘conventional’ hybrid buses over the next three years would increase the number of hybrid buses in London to over 1,600 by 2016. This would represent Europe’s largest fleet of hybrid buses.

It should be noted that the reliance on hybrid bus technology as a means to reduce emissions is a rather risky proposition. The emission and fuel economy benefits of hybrids—often claimed to be as high as 30-40%—have been rarely seen in real operation. A number of transit agencies that purchased hybrid buses found that the fuel savings were actually less than 10%. The City of Ottawa, the Canadian capital, has started a program to convert their hybrid buses to conventional diesel power, as the hybrids failed to deliver the expected fuel savings and showed high maintenance costs due to frequent battery replacements. If hybrids are not experiencing the fuel consumption benefits, they are not likely to produce the NOx reductions either. Interestingly, a study by NREL found significant NOx and CO₂ increases with a MY 2008 hybrid bus compared to a similar MY 2008 conventional diesel bus.

The Bus for London is a new, hybrid double-decker bus specifically designed for London, to replace the iconic Routemaster bus. The design objectives called for a fuel efficiency improvement of as much as 40% compared to conventional diesel buses, and 15% compared to hybrid buses already in operation in London. The first bus was put in service in London in 2012.

In addition to bus fleet hybridization, other measures are considered for future stages of the London LEZ program:

• New Euro VI buses—the Mayor proposed an £18m program to retire the last 900 Euro III buses in London so that all of TfL’s bus fleet would be Euro IV compliant or better, for all emissions, by the end of 2015.
• LEZ for construction machinery—construction sites are responsible for 12% of London’s NOx emissions. To tackle that, the Mayor will introduce a new Low Emission Zone for construction machinery.
• Zero emission taxi—the Mayor has asked his team to explore the potential of taxi designs that offer no emissions at the point of use.

The London LEZ program imposes restrictions and fees on the operation of more polluting heavy- and medium-duty vehicles within the zone limits. Older vehicles have to be upgraded to cleaner emission standards or retrofitted with emission controls such as diesel particulate filters. Since 2008, emissions of PM₁₀ and PM_2.5 in the city have been reduced by 15% and emissions of NOx by 20%, according to the Mayor of London, in part due to the LEZ program. Defra has formally reported that in 2011 London met the EU requirements for PM₁₀ for the first time.

Source: Mayor of London