Editing London congestion charge (section)

====Traffic speeds====
The charge operates for under one third of the hours in a year and covers around two-thirds of the central London traffic.<ref name="tfljune2007" /> In total 8% of traffic kilometres (miles) are affected by the scheme.<ref name="tfljune2007" /> TfL have extrapolated the trends in road speed in the congestion zone; they have suggested that speeds would have dropped from 17&nbsp;km/h (10&nbsp;mph) in 2003 to 11.5&nbsp;km/h (7&nbsp;mph) by 2006, had the scheme not been put in place.<ref name="tfljune2007" />

A report by TfL in early 2007 indicated that there were 2.27 traffic delays per kilometre (3.65 per mile) in the original charging zone. This compared with a figure of 2.3 per kilometre (3.7 per mile) before the introduction of the congestion charge. After the scheme was introduced they had measured an improvement in journey times of 0.7 minutes per km (1.1 per mile), or 30%. This improvement had decreased to 22% in 2006, and during 2006 congestion levels had increased so that the improvement, compared to the year before the scheme, was just 7%. TfL explained this as a result of changes to road priorities within the zone, delays caused by new pedestrian and road user safety schemes, and, most particularly, a doubling of road works in the latter half of 2006.<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/england/london/7109727.stm |title=Congestion charge 'not working' |date=23 February 2007 |work=BBC News   |access-date=23 November 2007 |archive-url=https://web.archive.org/web/20150429041334/http://news.bbc.co.uk/2/hi/uk_news/england/london/7109727.stm |archive-date=29 April 2015 |url-status=live}}</ref> Utilities were encouraged to complete planned road works in the year preceding the congestion charge, so it would appear that the first year of measurement used for later comparisons would also have been affected by streetworks to some extent.<ref name="bbc20070711" /><ref>{{Cite news |url=https://www.telegraph.co.uk/news/uknews/1454446/London-congestion-charge-not-working.html |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/news/uknews/1454446/London-congestion-charge-not-working.html |archive-date=12 January 2022 |url-access=subscription |url-status=live |title=London congestion charge 'not working' |first=Paul |last=Marston |work=The Daily Telegraph |date=16 February 2004 |access-date=24 November 2007}}{{cbignore}}</ref>

TfL reported in January 2014, that despite a reduction of traffic volume within London, traffic speeds have also been getting progressively slower over the past decade, particularly in central London. TfL explains that the historic decline in traffic speeds is most likely due to interventions that have reduced the effective capacity of the road network to improve the urban environment, increase road safety and prioritise public transport, pedestrian and cycle traffic, as well as an increase in road works by utilities and general development activity since 2006. This explains the lower levels of congestion reduction compared to the pre-charge baseline: 8% in 2006, compared to 30% in 2004. Since 2006 this trend towards slower traffic movement has ceased and traffic speeds have remained more stable, as evidenced by GPS satellite tracking data from 2006 to 2012. Indicators of excess delay or congestion also suggest a stable overall picture, with some improvements in the past two years. TfL concludes that while levels of congestion in central London are close to pre-charging levels, the effectiveness of the congestion charge in reducing traffic volumes means that conditions would be worse without the Congestion Charging scheme.<ref name=2014assessment/>