London's Ultra Low Emission Zone: the Evidence and Analysis Behind the Policy Development



London's Ultra Low Emission Zone: the Evidence and Analysis Behind the Policy Development

Authors

Claire Cheriyan, Transport for London

Description

The Ultra Low Emission Zone (ULEZ) is an ambitious proposal from Transport for London to reduce pollution in the Capital. This paper will discuss the evidence base and assessment techniques that underpinned the policy development process.

Abstract

The Ultra Low Emission Zone (ULEZ) is an ambitious proposal from Transport for London to reduce pollution in the Capital. The ULEZ is a traffic management scheme, based on the principles of the existing London-wide Low Emission Zone, and designed to encourage those that drive into central London to use low emission vehicles from 2020. This will significantly reduce the number of people living in areas of poor air quality and will help address London’s environmental challenges. The development of the ULEZ proposal has led to a national debate on the impact of diesel engines and a rethink on how public health issues can be addressed through transport policies.

This paper will discuss the evidence base and options assessments that underpinned the development of the ULEZ. It will look at how different tools and data were applied at each stage.

In the early stages, emissions inventory data and traffic counts were essential in identifying key sources of pollution and shaping viable options for the scheme standards and operating hours. With this shorter list of options we were able to develop a bespoke behavioural modelling methodology to understand how people would respond to different standards and charge levels as well as estimate, at a high level, the impact on vehicle kilometres and pollution.

At the latter stages we complemented the work with stated preference surveys and traffic modelling and the final proposal was assessed in terms of its air quality and health impacts.

Even after the proposal went to consultation we continued to collect evidence, specifically on the effectiveness of Euro 6/VI vehicles in real-world driving conditions. This is essential given the uncertainly and lack of confidence in the Euro standards delivering in the real world.

Publisher

Association for European Transport