Evaluating London's congestion charge – an approach using the macroscopic fundamental diagram

The rationale of road-pricing schemes is to reduce the negative externalities of road traffic by increasing costs to decrease demand. Although in the transportation literature this is a well-acknowledged means of relieving cities from congestion, only few cities have introduced such schemes so far. One of the most notable examples in Europe is London’s congestion charge. Motorists entering London’s city center are required to pay a fixed levy during working hours. The revenue generated by this levy is partly dedicated to improvements of the public transport system. The benefits of this congestion charge have only been analyzed from an economic perspective without reference to its impact on macroscopic traffic indicators. The recently introduced macroscopic fundamental diagram (MFD) and its extension to multimodal traffic, the 3D-MFD, offer a novel framework to address this gap.
In this paper, we analyze the performance of London’s overground traffic with the empirical 3D-MFD covering both car traffic and buses. Data is acquired from loop detectors (for car traffic) and automated vehicle location devices (for buses).