Understanding and managing congestion on London roads

A newly published study into congestion on London's roads concludes that a long-term strategic solution requires a shift to active, sustainable and space-efficient modes. Road space should be reallocated to walking, cycling and public transport;  there should be distance-based road-user charging;  there should be workplace parking levies;  and new developments with minimal or zero parking.

Understanding and Managing Congestion was commissioned from Integrated Transport Planning Ltd (ITP) by Transport for London (TfL) on behalf of the Greater London Authority (GLA). The brief was to identify the key causes of increased road congestion in Central, Inner and Outer London over the last five years and to identify a set of prioritised actions to address London’s congestion problems. The Study was developed between June and November 2017.

The study's conclusion is that the long-term solution is to manage demand for travel and promoting "modal shift":

"The contributory factors to traffic and congestion are multiple and varied, and unpicking the relative impact of individual factors is challenging. Analysis has identified recurrent demand on the network as the principal cause of congestion, with excess demand and events such as roadworks, accidents and breakdowns playing a notable but lesser role. As such, while it remains important to continue to invest in managing the network efficiently to minimise the impact of works and improve the response to incidents, this approach can ultimately not be expected to ‘solve‘ traffic congestion. Interventions must therefore focus on managing the demand for travel and promoting modal shift.

"A shift to active, sustainable and space-efficient modes provides the long-term, strategic solution to London’s congestion problems."

Key recommendations are as follows:

• Prioritise the efficient use of space in the allocation and re-allocation of road space. The most space-efficient means of moving people – walking, cycling and public transport – should be prioritised over low-occupancy private transport;
• Adopt the policy of introducing variable, distance-based road user charging at a London-wide level. A scheme should be designed to optimise its air quality, carbon and congestion benefits, while giving due regard to equity impacts. Revenue from the scheme should be used to improve public transport, walking and cycling;
• Review the present Congestion Charge exemptions and discounts, removing them unless their social value strongly outweighs the adverse impact that exempting vehicles has on congestion levels in the Zone;
• The London Plan should focus new residential development in areas with excellent public transport, and support high quality, high density developments with low or zero parking in these locations;
• Review the present regulatory regime for private hire vehicles, including a potential change to the law to allow TfL the power to limit the number of vehicles licensed;
• Continue with the delivery of bus priority schemes to support reliability of bus journey times and implement pilot schemes to explore the impact and attractiveness of express service operation, bus rapid transit and demand-responsive services on appropriate corridors;
• Implement workplace parking levies in Metropolitan Centres or borough-wide;
• Support freight by developing a London-wide integrated system of consolidation centres; encouraging sustainable delivery methods such as cycle freight and exploring the potential for freight-only lanes; and
• Make further investment in intelligent traffic management including the Surface Intelligent Transport System.

The Path of Enlightenment from vehicle-centric to health-centric

An interesting observation included in the study concerns the way transport policy has been evolving internationally;

"The development of policy to this point has followed a "path of enlightenment", from vehicle-centric to health-centric. The car-based focus of the 50s and 60s progressed to an emphasis on efficient movement of people, following the recognition that building more roads as a solution to traffic congestion was ultimately self-defeating. However, as with the car, enhancing the opportunity for personal travel leads to generated demand through greater numbers of person trips or longer distance travelled. This leads us beyond focusing on the transport network as an enabler of ever greater travel opportunities and towards enhancement of quality of life."

This is illustrated using a diagram produced by a Europe-wide study into congestion reduction, reproduced in the box below.