Traffic counts
The Royal Borough of Greenwich periodically conducts traffic counts to gauge vehicular movement throughout the borough.
These counts are performed using Metrocount pneumatic tubes, which are strategically positioned across roads to record traffic data. Each vehicle's passage over the tubes ideally results in accurate vehicle and speed recording.
However, research, including a notable study by McGowen and Sanderson, raises concerns about the reliability of this method. The study characterises the data as 'suspicious', highlighting significant discrepancies in vehicle counting and speed measurement due to both undercounting and overcounting.
Factors contributing to inaccuracies in pneumatic traffic counting include:
- Vehicles parked on top of the tubes, especially in residential areas
- Vehicles moving slower than 10 km/h (approximately 6 mph)
While Metrocount claims their pneumatic counters maintain an error margin of 1%, other studies suggest a practical error range between 7% and 12%.
The implications of these findings are significant, particularly in the context of traffic flow on boundary roads in both East and West Greenwich. Data indicates these areas experience the highest traffic volumes, which starkly contrasts with the council's proposed access restrictions under the 'Greener, Safer Greenwich' Traffic Management Scheme.
This discrepancy not only challenges the rationale behind the scheme but also raises concerns about the council's commitment to safeguarding the health and wellbeing of its residents, particularly those in economically disadvantaged areas.