1.  INTRODUCTION

  London Underground has been asked by the Urban Affairs Sub-committee of the House of Commons Select Committee on Transport, Local Government and the Regions, to submit evidence to the inquiry into Tall Buildings. The committee is interested in the relationship between tall buildings and transport capacity in particular the capacity of the Underground to carry office workers at peak times to and from tall building locations.

  This memorandum discusses the key issues for London Underground. These include:

—  overall transport demand and capacity;

—  location and distribution of demand;

—  impacts on train services;

—  impacts on stations;

—  handling disruptions;

—  timescales for planning and implementing new capacity; and

—  funding new capacity.

  The memorandum also discusses the potential locations for tall buildings and their impact on public transport usage.

2.  OVERALL TRANSPORT DEMAND AND CAPACITY

  Roundly 390,000 passengers enter the Underground in the morning peak hour (08.00 to 09.00). This level of demand creates a significant crowding problem for London Underground and its customers. There is some evidence that any increase in the level of congestion would lead to more people travelling outside the peak hour or avoiding central London.

  Over the next twenty years London Underground expects the demand for peak travel to rise by around 15 per cent. In response it is seeking to provide additional capacity of a similar level. In aggregate this should hold congestion broadly at today's levels. The additional capacity will be evenly spread over the existing lines except for the Jubilee Line where LUL is looking at an extra 60 per cent capacity to meet growth in Docklands. New rail capacity such as Thameslink and Crossrail in addition to upgrading the existing network should reduce congestion.

3.  LOCATION AND DISTRIBUTION OF PEAK DEMAND

  It is very unlikely that additional demand will be evenly spread across the Underground network. The location of commercial development and residential growth will each influence the pattern of demand. Over the past 20 years London Underground has seen an overall growth of 35 per cent in peak demand. Some areas however have lost demand for example the West End, others have seen employment demand double eg redeveloped suburban centres like Harrow, Hammersmith and Wood Green, while the Isle of Dogs has grown from nothing to a major employment quarter.

  Overall the stronger growth has been seen on the east side of central London, the City and Docklands generating relatively more demand on lines serving these areas for example the Northern City branch. There is some evidence that areas with significant development have drawn demand away from areas with very little development.

  Additional employment is not only provided by tall buildings eg Canary Wharf Tower but also "bulky" development for example the Broadgate Complex.

  The transition of extra employment into extra London Underground journeys is also located dependent. In the City virtually all the demand will use public transport but LUL will carry only 40 per cent to 50 per cent the rest being mainly served by National Rail. On the other hand for West End developments LUL would have probably and 80 per cent mode share.

  The capacity to handle extra growth will also depend on the proportion of demand arriving in the peak hour. Over the years the proportion of the peak three hours using the peak hour has fallen. If it continues to fall extra peak capacity becomes available. However congestion would then become more widespread in the shoulders of the peak eg 07.00 to 08.00.

  A number of locations have been discussed as key growth employment poles in the future eg Docklands, the fringes of the City, Kings Cross Railway lands, may be prime candidates for tall buildings. On the residential and regeneration side, Thames gateway and Lea Valley are potential important development locations.

  The implications for train services and stations are discussed in more detail in the next section.

4.  IMPACTS ON TRAIN SERVICE

  The busiest points on the network for train services tend to be just inside the ring of mainline termini for example between Victoria and Green Part on the Victoria Line. Additional employment inside this ring will increase congestion at these points. In most cases the load however will be spread across two or three lines. So long as the total growth is within the 15 per cent capacity of the train service congestion will not worsen.

  For developments around mainline termini, LUL can handle proportionately more assuming that there is additional capacity on the mainline. It does mean however that links approaching the mainline termini become virtually at peak load. This makes the management of flows boarding and alighting train at the mainline termini very critical and may limit the ability to provide higher peak hour frequencies.

  Developments around suburban locations do not provide any congestion risks for the train service. Indeed they may siphon off demand that would have travelled into Central London. However suburban locations are more likely to increase road traffic unless accompanied by strict parking limitations.

  Most of the development poles are on or near the ring of mainline stations. The major exception is Docklands where the Jubilee line is the major public transport artery. The development of the Docklands and the capacity of the Jubilee line train service are therefore very strongly linked.

5.  IMPACT ON STATIONS

  The impact of new developments on stations is less easy to judge without looking station by station. The capacity of stations varies considerably. Some stations just served by lifts can be overwhelmed by even modest development as occurred around the Angel station in the late 1980s. Some large stations have limited capacity for additional traffic before major congestion sets in, the current Kings Cross station is in this category. Other stations are already trying to handle demand above their capacity for example Victoria.

  In some cases LUL has schemes of live projects to expand capacity. The additional capacity at these stations will be substantial. When rebuilding stations our planning principles would normally seek to provide an additional 30 per cent to 50 per cent above expected future demand to give headroom for further expansion without a further and expensive rebuild of the stations.

6.  HANDLING DISRUPTIONS

  From time to time there are incidents on the Underground which cause short term closures of stations or sections of line. In such circumstances it is very valuable to be able to divert passengers to other nearby stations or lines. It is preferable therefore for major developments be located near a number of transport routes where possible.

7.  TIMESCALES FOR IMPLEMENTING NEW CAPACITY

  As can be seen from the previous discussion there is likely to be capacity in the long term to handle additional employment journeys on the Underground. However, new capacity has a long planning and implementation timescale. A new line or line upgrade typically takes 10 years from the start of planning to running the new services. At the very early stages demand and planning assumptions need to be fixed to allow design work to take place.

  Early indications from planning authorities or developers about development intentions are therefore vital. Where development poles or clusters are being considered it is appropriate for the land use authorities to discuss with the transport provider's potential transport capacity. The Channel Tunnel Rail Link is a successful example of where station and line capacity around Kings Cross was built into the planning of the link.

8.  FUNDING NEW CAPACITY

  The ability of the transport network and the cost of additional capacity to handle additional demand, will vary considerably from location to location. London Underground will have many calls on its funds not least maintaining and renewing existing assets. Additional capacity is unlikely to be funded from fare box revenue and therefore will need public funding unless supplemented by developer contributions. London Underground will have its investment priorities based on handling existing problems and overall growth.

  Where development creates a local capacity problem beyond LUL's plans and priorities there may be a case for developer contributions to part fund capacity expansion.

9.  TALL BUILDING LOCATION

  For aesthetic, environmental and planning reasons tall buildings will probably be limited in their location. If cluster development (including bulky buildings) is preferred then the previous discussion on growth poles is pertinent. One area for which large development is often appropriate for commercial reasons is directly above railway lines where the cost of rafting over the lines needs to be defrayed by dense development above. To the extent that such developments help fund transport operations and lessen the take on existing land use there may be a role for large or tall buildings above railways.

  Residentially the use of tall buildings near public transport modes is an alternative way of boosting the supply of housing without taking extra green field land and having to spend significant sums servicing the new, developments with new often less accessible, transport links.

10.  CONCLUSIONS

  London Underground should have the capacity to handle extra development through tall buildings so long as detailed evaluation of capacity is carried out at the potential growth locations and additional capacity planned and implemented in good time. This needs to be combined with policies to limit extra growth to what is economically efficient to provide from existing and future enhancements.