I am pleased to see that our paper:

Urban Low Emissions Zones A Behavioral Operations Management Perspective

is published now in the journal Transportation Research Part A: Policy and Practice. This is joint work with Virginie Lurkin and Julien Hambuckers. I can be freely downloaded here.

Environmental traffic restrictions are increasingly implemented in a large number of cities. One popular strategy consists in setting up Low Emission Zones (LEZs) that regulate or restrict the access to a dedicated urban area, for different classes of polluting vehicles. While LEZs are growing in numbers, there is a lack of objective evidence on when and how they actually contribute in reducing air pollution.

The main objective of this paper is to show how different LEZ setups lead to different impacts on air pollution. To do so, we use a conceptual framework based on simulated traffic data and behavioral hypotheses.

We identify three main dimensions (in short, VAT) for setting up LEZs.

• Vehicle. Depending upon the fuel used (diesel, gasoline, electricity, etc.) and/or engine age, access to the LEZ is limited. Usually, older vehicles (e.g. based on the Euro emissions standards) are banned from the LEZ area, assuming this leads to a better living environment for the inhabitants. In the extreme case, we have a zero-emission zone (ZEZ) where only zero-emission vehicles (e.g. electric vehicles) are allowed.
• Area. The actual geographical region depicted as LEZ is an important dimension. A large number of variations exist, ranging from streets, over neighborhoods, to complete downtown areas.
• Time. This refers to the time period during which the LEZ is “open” for vehicles. Some LEZs do not allow vehicles to enter a given city area during certain periods of time.

Our analysis highlights that the impact of LEZ on air pollution does not only depend on the severity of the operational rules, but also on its interaction with the behavior adopted by road users, and calls for ex ante considerations of these aspects before establishing the LEZ.

Important is to assess the impact of bypassing the LEZ. An increase in emissions outside the LEZ arises from additional distance covered by road users who chose to bypass the zone. These extra kilometers traveled induce extra emissions, illustrating the importance of including road users’ behavior when assessing the effectiveness of LEZs.