TfL Ref: FOI-0292-1718

Thank you for your email received on 10 May requesting information about Low Emission Bus Zones (LEBZ).

Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our Information Access Policy. I can confirm we do hold the information you requested. You asked:

In the last year, TfL announced that certain London routes had qualified for Low Emission Bus Zone (LEBZ) status, and the criteria for choosing these routes was as follows:

1) They are outside the Ultra-Low Emissions Zone, where buses will be upgraded to meet those standards anyway;

2) They are predicted to exceed legal limits in 2020 unless we do something; and 3)At least 40 per cent of road based emissions were due to buses.

With regard to point 3 above, please provide detail on the particulates referred to as well as methodology, assessments , actual on-site monitoring and evaluations undertaken by TfL, which led it to conclude that 40% of road emissions were due to buses for the qualifying LEBZ routes.

In other words, what particulates, what on road monitoring tests did TfL undertake in respect of the air quality environments for each qualifying LEBZ; or was this 40% figure arrived at from off-road testing of its buses?

The road based emissions figure mentioned were based on the data present in the 2013 London Atmospheric Emissions Inventory (LAEI) survey. The LAEI survey provided combined estimates of key “link level” emissions:

• Nitrogen oxides (NOx)
  
  
• Particulate matter with aerodynamic diameter < 10 μm (PM10)
  
  
• Particulate matter with aerodynamic diameter < 2.5 μm (PM2.5)
  
  
• Carbon dioxide (CO2)

The study also including a number of subsidiary pollutants, as well as the proportion of emissions contributions across various vehicles types, i.e. cars, buses, LGVs or taxis.

The full report can be viewed using the below weblink:

https://data.london.gov.uk/dataset/london-atmospheric-emissions-inventory-2013

The link level emissions data used for the identification of the potential Low Emission Bus Zones are available in section 3 (Detailed Road Transport). 

The emissions estimates provided were based on vehicle emission factors and traffic data contained within the above report. The methodology for this is also set out in the “Method” documents available on the datastore link above.

Predicted concentrations are also available on the datastore and these were used to identify the areas where nitrogen dioxide levels are predicted to exceed air quality limits.

If this is not the information you are looking for, or if you are unable to access it for some reason, please feel free to contact me.

Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.

Yours sincerely,

Melissa Nichols

FOI Case Officer

FOI Case Management Team

General Counsel

Transport for London