Travel in London Travel in London

4. Performance of the transport networks
Table 4.7
Mode
Total yearly capacity provided by the principal public transport modes.
Million place-kilometres.
2008/09 2013/14 2014/15
Percentage
change
2008/09 to
2014/15
Percentage
change
2013/14 to
2014/15
Underground 64,193 67,328 70,493 9.8 4.7
Bus 28,817 29,605 30,057 4.3 1.5
DLR 1,715 3,234 3,291 91.9 1.8
London Tramlink 556 632 629 13.1 -0.5
Source: TfL Planning, Strategic Analysis.
Notes: Values for Underground have been revised to reflect published London Underground assumptions for standing
capacity. The absolute values given in the table reflect these revised assumptions, and are internally consistent. They do
differ, however, from equivalent values published in previous Travel in London reports, although the percentage changes
between years are the same.
*Figure re-based mixed operation double deck capacity on certain routes.
Since 2008/09, Underground, bus and London Tramlink capacity has increased by
9.8 per cent, 4.3 per cent and 13.1 per cent respectively. DLR capacity has
increased by 91.9 per cent over the period, following line extensions to Woolwich
Arsenal and Stratford International.
4.12 Performance of the road network for movement by motorised
vehicles – average traffic speeds and delays (congestion)
Introduction and content
This section updates established indicators of road network performance in
London, looking at average traffic speeds and delay (congestion) levels, based on
Trafficmaster GPS data, as well as TfL’s indicator of journey time reliability on major
roads. These indicators focus on motor vehicle traffic only, and provide a relatively
short-run view broadly corresponding to the term of the current MTS.
Established measures of road network performance in London
There are three established measures of road network performance for motor
vehicle traffic:
• Average traffic speed is the simplest measure, but does not indicate how actual
network performance compares to what might be ‘expected’ for the network.
This would vary, for example, between major and minor or residential roads.
• Excess delay is the conventional measure used to describe traffic congestion. It
compares the actual travel rate (in minutes per kilometre) for a given journey
against the travel rate for the same journey under uncongested conditions
(typically and for practical purposes taken as the overnight period).
• Journey time reliability is the MTS outcome indicator for traffic smoothing,
which quantifies the variability of actual journeys around a nominal average. The
measure is independent of both absolute average speed and delay. This
measure is described more fully in Travel in London report 3.
These are essentially ‘pragmatic’ measures that provide a good and consistent
overview of the performance of the road network for general motorised traffic.
However, TfL is also giving consideration to potential other measures that could
85 Travel in London, Report 8