Keeping our capital working for the UK

Print this page

New big data reveals the reasons for London’s congestion

A new report from traffic analysts INRIX, ‘London Congestion Trends’, has used big data to highlight the reasons for London’s growing traffic problem.

The in-depth study of the causes of traffic congestion in London between 2012 and 2015, identifies roadworks and goods vehicles as the main causes of congestion, but shows that travel demand in central London is flat or decreasing.

The report’s findings show that:

  • Congestion in London has risen noticeably between the years of 2012 and 2015 with journey times in Central London increasing by 12% annually;
  • Car traffic, including taxis and private hire vehicles (PHVs), is actually decreasing in Central London and the Congestion Charge Zone;
  • Vehicle counts are flat or decreasing in Central London and increasing only slightly in Outer London; increased use of alternate modes of transit may explain why;
  • Light goods vehicle traffic is increasing in Central London, possibly related to the rise in ecommerce;
  • One of the most significant drivers of increased congestion in London is roadworks, increasing 362% during the period.

David Leam, infrastructure director at London First, chaired a roundtable breakfast at Ashurst to present the findings to members.

The chief data scientist of INRIX, Dominic Jordan, spoke to launch the report. You can view Dominic’s presentation here.

This brought together a rich package of data from the public sector, which until now was not readily available in one place, alongside private data from INRIX themselves and Uber.

This clearly showed that while traffic demand is broadly static, and all car traffic in central London is actually decreasing, congestion has significantly increased. The two key increases it identifies are the rise in vans and the sharp rise in roadworks, both planned and unplanned.

The Evening Standard covered the report, quoting David:

“London’s roads are increasingly congested, but this isn’t down to a boom in car journeys.

“As this report shows, car traffic is actually decreasing in central London, while van traffic and roadworks have risen significantly.

“What’s needed is for the new mayor to ease off excessive roadworks, build new river crossings, devise a plan for managing freight and revisit measures to control congestion, including charging.”

David previously wrote in City AM about the need for the next mayor to take radical action on London’s road congestion.

We will be running a strand of work on roads through this year, including the topic of congestion.

If you would like to know more about this work, please contact: Richard Dilks,

London First Tweets