- The traffic growth phenomena has been well known since the 1960’s and was the subject of the seminal “Traffic in Towns” Report, which described the mechanism like digging a ditch in a water logged field. Buchanan in that report concluded that congestion could only be resolved by providing public transport that will attract marginal car trips, so releasing road space.
- A tram network delivers 90% of the benefits of an underground system but at 10% of the cost. *
- Trams have a much higher passenger carrying capacity on congested lines than buses.
- If all costs are taken into account (capital cost, vehicle life, cost of capital ( much lower for trams) , on suitable high traffic routes, the overall cost per passenger km of a tram is about half that of a bus.
- If city bus and tram timetables are compared all over Europe it is clear that trams can operated at a far shorter service interval and for a greater part of the day.
- Most if not all exclusively bus based congestion cutting schemes have been a failure, certainly in the UK witness Swansea which spent £10 million and has now abandoned it. https://bathtrams.uk/difficulties-and-problems-encountered-with-bus-rapid-transit-in-the-uk/
- It is is self-evidently wrong to suggest that road widening to cut congestion will somehow cut pollution by removing slow moving vehicle engines which are less efficient and so more polluting than fast moving traffic. Any benefit will be far outweighed by the greater number of vehicles passing at higher speed.
- Metro stations are widely spaced, so are inconvenient for many local trips. Additionally some people find underground railways and stations to be claustrophobic, and very few new Metros are being built in Europe. In cities with both a Metro and tramway, because of the closer stop spacing, journeys under 5 miles long are faster by tram.
Protracted access times from surface to platform are an additional disadvantage of underground metros quicker to walk tube map – Google Search
Trams do not require wide streets and segregated routes – Lisbon below.
This so called on street running is commonplace in many continental cities, with the trams having general city wide coordinated priority ( Green Wave Traffic Light Priority) and the trams acts as a form of car restraint and can be seen leading cars in unimpeded by cars in as in Brussels.
- Although buses can have some priority at individual traffic light, this is not the same or as effective as ( Green Wave Traffic Light Priority) which is generally not applied to buses for various practical reasons ( World Bank).
At traffic pinch points cars and trams can share the same surface if necessary, see Prague https://www.google.com/maps/@
50.0829092,14.4045128,3a,58. 7y,314.42h,77.14t/data=!3m8! 1e1!3m6! 1sAF1QipOvE479HdbfIcp6y3clLU- jUGL1n1vSQk_qlNbp!2e10!3e11! 6shttps:%2F%2Flh5. googleusercontent.com%2Fp% 2FAF1QipOvE479HdbfIcp6y3clLU- jUGL1n1vSQk_qlNbp%3Dw203-h100- k-no-pi1.388438-ya188.89844- ro-3.0117838-fo100!7i7680! 8i3840
- MetroBus type schemes which use concrete guided busways, unlike trams, cannot share road-space with cars or emergency vehicles and are therefore problematic to get into city centres.
- Prof Lewis Lesley argues against using so called Metrobuses or any bus based rapid transit as a cheap substitute for trams: “WECA is misguided in opting for Metrobus mass transit, as experience has shown that motorists are very resistant to using any form of bus, which has been demonstrated continuously since the pioneering Busway was opened in Runcorn New Town which was designed to be based on bus transit, in 1970. A significant percentage of motorists are however willing to switch to rail services, whether Trams, Light Railways, or ordinary suburban trains. The average on UK Tramways is that 25% of passengers have left a car at home. In the USA the figure is 35%”
- An argument against rubber tyred vehicles was recently reported by Emission Analytics, which showed that a large volume of particulates can be generated from the road-tyre interface including existing road dust as well as that from brakes and re-suspended tyre dust. The resultant numbers of particulate suspension can be orders of magnitude in excess of tailpipe emissions.
- Research in the USA shows that to get motorists to use rail schemes the service interval must be shorter than the car journey time. With a half hourly frequency, car journeys will need to be longer than half an hour. There can be few car trips in Bristol that will take more than 30 minutes.
- Taxi use is highest in the poorest quarterly UK households (mostly carless). The next biggest users are the top quartile households. This reinforces/confirms market research over the last 40 years that cost is not a big determinant of bus use. Quality of service is the real decider. Often this is people’s perception of the quality of service, rather than an actual one, since it may have been decided by the one day the car was in the garage for repair, and the bus did not turn up or was late. This is why trams not only has a better perception of service quality but also provides a high quality service: smooth riding, plenty of space and on time/fast travel.
- Only about 11% of tram passengers use a free (pensioners) pass, compared to 35% of bus passengers. This either means that pensioners do not like trams or actually four times as many people will buy a tram ticket as compared to bus travel  . In Bath are 68% of trips are by car and 6% by bus.  Extract of letter from Prof Lewis Lesley, Emeritus Professor of Transport, Liverpool University, pers com.  The reasoning is not at first glance obvious. Consider a tram and a bus each with 100 passengers. The tram will have 11 pensioner passes and 89 payers. The bus will have 35 pensioners and 65 payers. Now imagine that we increase the size of the tram so that there are now not 11 but 35 pensioners, so by proportion the payers, 89 in number, will have to increase by the ratio of 35/11 = 3.18. Thus it will have 89 x 3.18 = 283 passengers. 283 / 65 = 4.35.
- In Bath 68% of trips are by car and 6% by bus. https://bathtrams.uk/evidence-that-car-drivers-will-switch-to-trams-but-not-buses-1/
- There are two additional problems – since deregulation buses outside London have become less simple (need for several different operators’ tickets), relatively more expensive and less comprehensive (eg: no service after 7pm in many places), and the British approach to tariffs based on distance rather than time and with few group tickets makes a taxi a far cheaper option when travelling as a couple and certainly as a family.
- About a fifth of journeys are walked (because they are short). Similarly only 25% of trips are over 5 miles long and less than 3% over 30 miles.
- Excluding cars from city centres is cheap, quick and effective. It dramatically reduces congestion and pollution. We can see it working well within the bus-gate scheme in Bath and in these places round the world: https://en.m.wikipedia.
org/wiki/List_of_car-free_ places However for the city to survive commercially an alternative acceptable to motorists must be provided and this is not buses.
- BUT car trips dominate all trips, even within Bath, where nearly 70% are made by car and less than 10% by bus.
- Other European cities have shown that public transport usage can be increase to over 20% of the market – Freiburg is a good example, not by low fares or free services but by opting for or expanding tram systems, which passengers prefer. There are many examples from France and Germany that show tram + bus can get over 20% of modal split, and car reduced to under 40%.
- While laying tramlines is expensive in first cost compared with buying buses just using existing roads funded by the council tax payers, the TOTAL cost to these same ratepayers of maintaining the roads once the heavy buses have started and trundled over them for a few years, gouging out potholes and releasing the material as Oslo Effect dust is very high. What then is the total cost of the road maintenance, bus maintenance, NHS costs for respiratory disease, etc.
*”Light Rail Developers’ Handbook” ISBN 978 1 60427 048 8 – Professor Lewis Lesley, Emeritus professor of transport planning Liverpool University – Page 5, which refers to Laconte P, 1978, Marketing and Public Transport, UITP Conference, Newcastle Upon Tyne