More on electric cars.

Catalytic convertor. Apart from carbon dioxide, many of these are lower from a car exhaust than those present in the average town.

nuclear electricity of course.

Trolley busses.

Indeed. Virtually NO sulphur or carbon monoxide out of a modern car exhaust on modern fuels.More ammonia in harry's urinals than in car exhausts too. And no unburnt hydrocarbons at all from hot exhausts - far more from fuel spillage at the pumps.

The one that is left is Diesel particulates. Very nasty, very carcinogenic.

Yes, in fact does anyone know why places like Manchester, Edinburgh, are putting in trams at ruinous expense instead of electric trolley busses? Apart from the willy-waving factor, that is.

Some people just like playing with bigger train sets.

So it's the railway anoraks again?

For Euro 5 compliant cars with a particulate filter, how much is the volume of particulates reduced?

I have no idea. Presumably a lot.

I've never seen any wisp of smoke out of mine (no actually tell a lie, once the engine failed to start at first attempt, and when it started on second attempt it belched out a small cloud).

My previous diesel (non Euro5, non DPF) would noticeably lay smoke e.g. getting up to speed on motorway up-ramps.

The price to pay is potential replacement of the DPF after a few years, and higher fuel consumption whenever it decides it needs to burn-off the trapped soot.

Trams make traffic jams. A waste of time in many cases. Manchester try to pass off Metrolink as rapid-transit. What a joke! Rapid transit has to be grade segregated.

Tram networks were considered outdated after WW2. Most disappeared. The Continent kept them up as the cities did not have the money to replace them. For some reason in the UK they had a renaissance, led by Manchester. Manchester's Metrolink is good as they are effectively tram-trains running on existing tracks and lines and using existing stations and run on streets. They interchange well - there is a Metrolink platform at Manchester Victoria station for ease of changing. The others tram networks are a bottomless pit for money with poor price performance. The ill-conceived Merseyrtram was rightly shelved

Still, the recent Merseytram project was a joke - they never learn. It never integrated with the Merseyrail metro, unlike Manchester's Metrolink. Stops outside stations is not integrating. I am glad HMG cancelled the whole joke.

The clown who was behind Merseytram, Neil Scales, lefta shambles behind. He was chief at Merseytravel. There is Merseyrail rapid-transit urban rail network which is underground in the centres of Liverpool and Birkenhead. Merseyside has an amazing level of disused rail infrastructure - and much mothballed. About 5 miles of disused tunnel under are awaiting reuse. The oldest tunnels in the world. The Wapping tunnel dates from 1829, is 1.25 miles long and was the first ever bored under a metropolis. So serious transport history here as well. This can be incorporated cheaply into Merseyrail metro.

Instead of extending the Merseyrail metro, in 2001 Scales went for a stand-alone street running tram network. It was not integrated into Merseyrail. Nearby Manchester wanted an underground metro but could not afford one so went for a street running tram network that also ran on old rail lines. The trams pulled up to platforms at local stations for easy transfer, and then ran onto streets - meshing in. See this, the Manchester Metrolink is mentioned as well.

The government approved Merseytram. £80 was spent in "consultancy fees" before a line was laid. The government rightly cancelled the lot in 2005.

"However, one of the greatest causes for concern is Revenue Deficit. Virtually all the attention is currently focused on the capital cost of the scheme (currently £450M and rising) with no apparent consideration of cost over-run which is inherent in all light rail projects or the possibility of revenue deficit if the project ever reaches fulfillment. In 2006, for example, Manchester's Altram accounts showed a loss of £8M due to overoptimistic passenger projections, while in the West Midlands the Midland Metro, also operated by Altram, showed losses of about £16M. Worst of all, down in London, Tramtrack Croydon Ltd recorded debts of £100M and was seeking financial restructuring in order to continue trading."

Then there is the Edinburgh debacle. What an expensive joke. Expansion of existing networks is feasible but I new tram networks apear dead.

Supecap, zero polution at point of running, buses, charging at each bus stop, made into a full guided bus network is far cheaper than street trams with many clear advantages all around, cost only being one. Trams only came about because the IC engines, road vehicles and roads of the late 1800s were all dire. Technology has caught up and traffic jam making trams are history.

CPOs are needed to string ugly and dangerous wires from buildings. The advantages of trams were a sense of permanence, and zero emissions in cities. Supercapacitor buses negate the latter and a sense of permanence is easily achievable using buses. Using platforms having no step to board a bus is easily done. Look at Bogotá's guided bus network.

DfT has been looking at new technologies and the supercap buses are a success and look the way to the future in urban areas.

R&D in fuel cell trains was under way for the past 10 years, especially in Japan - hence why HMG held back on electrification of surface lines keeping outdated and slow diesel trains. Running overhead lines for hundreds of miles is not cheap and them the maintenance costs on top. Fuel cell trains carried their own fuel. The technology did not come to fruition fast enough so HMG started to electrify lines like Liverpool to Manchester, London - Bristol, Great Western, etc.

Carrying capacity? Our newest 'Bumblebee' 5-section trams can take up to

government policy (at the time)

tim

for 95% of the route it is

tim

Course your city has to have been built from scratch with trams in mind, or if old to have wide boulevards. Most of which doesn't apply in the UK. Trolley busses don't, of course, have the limitations that trams have.

And being able to take 240 people is only useful if there are 240 people to take. More, smaller, trollies/busses are likely to be a better bet.

Ah, but petrol is no use for dipping your snout in the subsidy trough...

You can if there's a war on (well, sort of, coal gas) :-)

The camera never lies. Not only will you look a dork driving a Prius you are simultaneously trashing the planet.

Purchased at Newport Pagnell services, from the toy section.