How long do trams last compared to busses?

How long do trams last? I suggest it is best practice to quote the age when they are replaced, i.e. usually sold on to heritage collectors or a poorer city. That makes comparisons with busses easier. London busses now are replaced when only 8 years old but remain in use second hand till about 14 years. Trams are assumed to be replaced after 30 years and often are because by then they are likely to be technically obsolete and too costly to maintain and run compared with replacements. Most PFI franchises are also 30 years, so I say trams last 30 years before they are sold to other users. There is however a further complication when comparing to busses. Trams normally have a major refurbishment at 15 years, or it is written into the business plan as a cost at year 15; but busses are not normally refurbished by their first owner. At the Bristol BRT public inquiry I suggested that over a 30 year comparison timeframe the bus operator would have to purchase 3 fleets of busses but a tram operator would only purchase one fleet of trams. Unfortunately it was very obvious that no busway promoters or bus operators plan anything more than about 5 years ahead so my point was considered irellevant.
Trams do have metal tyres, which do not last 40 years, but they are not a high cost like rubber tyres.
I would be cautious about trams being able to go round tighter curves because there are penalties for doing it especially on steep hills.

Bob Chard

• Bob Chard – Town Planner and Transportation consultant. Member of UK Tram (Ultra Light Rail Group) 2012-present. M.A. Geography,  Oxford University,       Dip. Ed,  Education,  Oxford University,  Dip. T.P., Town Planning, Liverpool College of Building, 1968. B.A., Environmental Science, Open University, M.Phil., Architecture, York University IAAS. Bob Chard has over 40 years experience working as a town planner in UK and overseas; in local government, as a consultant and teaching in polytechnics and universities. For the last 20 years he has worked mainly on major transport infrastructure developments in London and the south east; with particular responsibilities for town planning and environmental aspects of project development and evaluation. He has particular expertise in:-

Consents procedures for transport infrastructure developments
Environmental resources protection and management
Town planning legislation; government policy and advice