From a historical point of view, it is worth noting that when many of the large UK trams systems ( the ones we have reliable data for) were replaced with buses, there was an immediate fall in passenger numbers by about 1/3 as the new bus users found the service unacceptable and so found other ways of getting to work, typically by purchasing a car:
This shows that German cities with trams and buses have on average 50% more public transport users than bus only cities. ( it should be noted that it could be that trams were installed to deal with the higher capacity needed, so its not necessarily causative.)
“The result is, that cities with a tram system have in average 50% more passengers in the total system (tram and bus) than cities with a bus only system.
Cities like Wiesbaden with an extensive bus lane system are among them.”
Great Britain: Parliament: House of Commons: Transport Committee – 2005 – Political Science
The Future of Light Rail and Modern Trams in the United Kingdom; Tenth Report of
|4. Select Committee on Environment, Transport and Regional Affairs Appendices to the Minutes of Evidence https://publications.parliament.uk/pa/cm199900/cmselect/cmenvtra/153/153ap14.htm
“ Docklands Light Railway: opened in 1987 and promoted originally by the London Docklands Development Corporation as part of its mission to regenerate the derelict areas around Poplar and the Isle of Dogs, the railway was revolutionary in its concept (and accordingly suffered well-publicised problems). Like Tyne & Wear, it is a railway with light carriages and a large proportion of existing and former railway formation for its trackbed (but with tighter curves and steeper gradients than “heavy-rail”). The actual operation of the railway is entirely by computer and is driverless. The system has been extended and is expecting a further extension to Lewisham to be opened before Christmas. Despite its adverse publicity, it has contributed very significantly in attracting business to the area, and his relieved traffic flows and congestion to a great degree in an area whose road network is old and constricted.” ( this means previous car drivers switched to the DLR – Ed)
France has re-installed 27 tramways since the war, specifically to regenerate city centres, and they have been successful by attracting car drivers:
“ Worldwide much comment has been made over the years over numerous new tramway and light rail systems. The European system which first attracted immense attention was that at Grenoble (1987), a medieval French city which shoe-horned a new tramway into a city centre, carried out many associated improvements in the city centre and revolutionised urban travel patterns ( ie they took the tram – Ed). Many years previously, the French government had taken the initiative by inviting a number of cities to submit plans for rapid transit systems in order to break the spiral of decay, congestion and environmental pollution—and offered massive finance to realise these projects. The majority of those invited opted for light rail, including Nantes, Grenoble, Strasbourg, and Paris; Lille and St Etienne took the opportunity to upgrade their existing tramways. Clermont Ferrand and Caen have opted for Guided Light Transit.”
4.29 Monitoring undertaken after the opening of Tramlink indicated that almost 20% of people using the system had previously made their trip by car, while modal shift from 21 Tyson, W (2004) – Personal Communication 22 Atkins and TSU (2000) – Supertram Monitoring Study: Final Report – SYPTE and DETR – pp. 4-2 to 4-5 23 Centro (2003) – Midland Metro User Survey – Ref. No. M10.03, pp. 11 What Light Rail Can Do For Cities: A Review Of The Evidence P:\projects\5700s\5748\Outputs\Reports\Final\What Light Rail Can Do for Cities – Main Text _ 02-18.doc 38 other public transport modes accounted for about 75% of demand. The latter is not surprising given that Tramlink both specifically replaced some existing heavy rail services and that TfL made changes to bus routes and services to take account of Tramlink operations. Indeed, given that many peak users of the system travel to, or from, Central London by onward rail connection and effectively do not have the option of using a car, the mode-shift from car is particularly impressive.
Comparative Mode-Shift to Quality Bus Schemes
4.33 While the effectiveness of light rail in attracting car users has been clearly demonstrated, the ability of bus-based schemes to affect significant mode shift in the UK remains largely unproven. A comprehensive study of existing schemes found overall potential passenger uplift from bus quality initiatives27 ranged from between 4.1% and 6.4% in the medium term (i.e. 3-5 years after implementation of all measures).
4.37 These responses are encouraging but, in comparison to light rail, suggest a much lower level of car transfer: • Typically, around 20% of peak light rail users have been found to transfer from car. In a peak hour, a typical system operating at, say, 6tph would have resulted in c.240 cars per hour removed from the road network. • Similarly, 20% of new bus users in a quality corridor might transfer from car and a 20% uplift in total demand might be achieved. At an overall level of service of, say, 30bph then c.40 cars per hour would have been removed from the road network.