>Incidentally I got a proposal to vote on the other day proposing changing Park Lane southbound into park land with cafes which I think would be nice.
It is unlikely to be happen due to the 'solutions' proposed in section 3.3.10 through to 3.3.13 (pg33). Which states that there is no will to implement any measures on this part of the thoroughfare by the incumbent landowners ─ any attempts to do so, have been thwarted for more than a century. The well heeled clientèle, do not particularly need a bohemian cafe culture at the doorstep nor do they care about pedestrians, especially when they arrive at the affluent hotels/hedge fund offices/ ballrooms/casinos, in their luxury automobiles to work & play. The addition of having access to exclusive shopping districts, restaurants, entertainment within spitting distance in any direction, further erodes any case for pedestrianisation.
However, there is a good case for lowering speed limit, modernising the subway access and creating more ways to cross between the central reservation, across to Hyde Park.
I imagine the land is owned by the government or the crown.
p33 says "Some of these solutions have been considered in the past, but have foundered, principally due to lack of resource" but that could change.
The road was expanded in the 60s:
>a major reconstruction programme in the early 1960s that transformed the road into a three-lane dual carriageway by removing a 20-acre (8.1 ha) section of Hyde Park
but I'm guessing the trends are a bit the other way now - less towards cars, more towards pedestrians.
I must be misunderstanding your comment. Are you advocating for the government to take a land owner’s property without any recourse? The land owner is given no choice in the matter? Seems awful.
Even if the subject weren't publicly owned land, the implication would be the opposite, that landowners should control their own land and not everything around it that doesn't belong to them.
There are plans to extend the ULEZ all the way to the North and South Circular ring roads, which will really make an impact. But won’t happen until Oct 2021.
Hopefully the good results here may help them push this date forward.
I seriously don’t understand why this post has been modded down, currently at -1. Seems inline with the rest of the anti-pollution sentiment on this thread.
I wish cars were banned from most back streets in central London, it's really not necessary to have every small road accessible by car. The only exception is unloading/loading at commercial places but that should only be at certain times.
How large/dirty of a vehicle should be allowed to load/unload anywhere? My city has very narrow, small, 1700's streets and there are not limitations on 18 wheelers blocking whole lanes of traffic to deliver a couple of hand-carts of perishables. Seems these trucking companies should be sub-dividing their parcels into more logistically manage-able sizes, but there is no cost associated to these negative externalities.
> Seems these trucking companies should be sub-dividing their parcels into more logistically manage-able sizes
Are you sure that trade-off of many smaller vehicles rather than one big vehicle makes sense, in terms of pollution and congestion? I'm not as sure as you are, but who knows.
There are thousands of roads in London that would benefit from bollards in the middle of the road, preventing rat running traffic from using them to bypass traffic on A and B roads.
I have absolutely no idea why this doesn't happen.
IME commuting by motorbike through London over the past 10 years, most side roads aren't viable rat runs owing to one way loops that feed you back out onto the road you're trying to avoid.
In north and east London, it's the canals and rivers that prevent a lot of rat-running. The Lee / Lea river and its reservoirs, all the way to the canals in Islington, down into Limehouse, cut out most alternative east-west routes - you need to cross those waterways by bridges, and only the bigger roads have bridges. And there are east-west canals too, that reduce the options north-south on the east side of the city.
I think how it works at the pedestrian mall here is all loading and unloading gets done before store opening hours and then the vans leave and the bollards go back up.
This is an important point but it's hardly that Central London is accessible to disabled people today.
Cities that get this right have good adaptations for disabled travellers - generally by permitting them as exceptional traffic (and not through traffic).
Plus, for example, door-to-door bike lanes are also good for powerchairs. You will see a lot more wheelchair users getting about anywhere in the Netherlands than you do anywhere in the UK.
The first half of the book covers some of the chemistry of air pollution along with a review of the impact that this can have on health (particularly scary is the discovery that PM0.1 can be found in the blood and may be attributed to cardiovascular disease). Later chapters then talk about how air pollution has been addressed in different places and finally there is some guidance on what you can do reduce your exposure.
I discovered this book from one of the episodes of Inside Science featuring the shortlisted books: it's still up if you want to listen yourself: https://www.bbc.co.uk/programmes/m0008jf1
Euston road isn't even subject to the congestion charge. Only side roads are.
Furthermore the vast majority of traffic circulating in C. London traffic all day are busses, Taxies, phvs and commercial vehicles. Not private vehicles.
There is nothing in that note which indicates how, when they came to these conclusions. It's pretty much impossible for the headline claim to be true as a result of the ulez.
Where is the supporting collateral? This is political grandstanding.
> Furthermore the vast majority of traffic circulating in C. London traffic all day are busses, Taxies, phvs and commercial vehicles. Not private vehicles.
Isn't that proof that the Congestion/ULEZ charges are working effectively?
They are saying over a recent six month period that that this ulez has reduced something by 33%. That's pretty much impossible as private vehicles largely affected by this ulez program are a fraction of the circulating traffic (which are vastly more pollution/no2 producing vehicles.
ULEZ does not only affect private vehicles, the list of who qualifies for a discount or exemption is pretty short (residents are exempt for now, taxis, historic vehicles, and things like agricultural and military vehicles or excavators, mobile cranes): https://tfl.gov.uk/modes/driving/ultra-low-emission-zone/dis...
According to the report, only 9% of all vehicles were exempt (38% of non-compliant vehicles, which were 23.2% of all vehicles in September). Everyone else either pays the charge (£100 per day for lorries, buses, and coaches), incurs a penalty, or upgrades their vehicles.
Say you're a national logistics firm. Your fleet is 60% compliant with the ULEZ rules. ULEZ comes in, and now your London deliveries are affected by this annoying payment, which is a cost to the business seemingly at random.
Big boss comes down. We floated telling London businesses this is a cost we're passing on. Every single one laughed and said they'd move to our competitors if we send a new contract through with increased prices. I'm supposed to deliver Q3 growth figures, "half our bloody London customers walked" is not growth. So, make a pool of vehicles that are compliant and make sure every London delivery uses that pool of vehicles.
Bingo, the eight year old truck that was scheduled to go to Charing Cross tomorrow is now headed to Derby and a six month old truck goes to Charing Cross. It's not a _lot_ but added up across the whole of the ULEZ it makes a difference.
ULEZ isn't "no diesel trucks" it's "only modern compliant diesel trucks". So the competitor doesn't need to pay the charge so long as either all their trucks are compliant OR as we do at the end of the example they use their noodle and allocate only compliant vehicles to London.
I would be _astonished_ if some and maybe all actual companies in that game hadn't gone "Oh, we need to ensure only our compliant trucks enter the ULEZ" back when this rule was written, long before it came into effect. The UK is full of archaic stuff that makes it awkward for a not-so-smart logistics company so "We mustn't send old trucks to central London" probably isn't even on the top ten weirdest scheduling constraints they deal with.
This is equivalent to asking why competing firms don’t simply agree to collude to stop innovating and fix prices, except in this case the colluding parties lose by paying a toll as opposed to reaping monopsony profits.
Given a meaningful incentive to do something within its means, a company will either do that thing or lose business to companies that do.
Anecdata, but a friend of mine is a flower seller in central London and she has just bought (actually some sort of monthly hire-to-buy scheme) an e-van for deliveries. She was driving a really dirty, ancient van before that and paying a fortune in ULEZ charges. She saving enough in ULEZ and petrol to make the change cost-neutral.
Looking at the report I don't really understand where your scepticism comes from there really does appear to have been a 36% reduction in NO2 readings over the period under consideration, an acceleration of an existing trend which the authors take into account in their modelling. They acknowledge the need for further monitoring to confirm that it's not an anomaly but given the existing readings it seems like the press release is making a reasonable representation of the science given the constraints of the format.
According to TFA, compliance with ULEZ standards increased from 39% of all vehicles in February 2017 to 61% in March and 77% in September. That means that a lot of those vehicles are no longer circulating in central London. And of the non-compliant vehicles, only 38% were exempt. That is 9% of all vehicles.
It's a disgrace that black cabs are allowed the exemptions they currently receive (bus lanes, ULEZ, congestion charge, waiting on double lines etc). They're an incredibly inefficient form of transport used almost exclusively by tourists and the wealthy and the non-PHEV are some of the most polluting vehicles on the road.
The black cab lobby enjoys a disproportionate amount of power when it comes to policy-making on transport. Most Londoners would not miss them if black cabs disappeared overnight but somehow huge allowances are made to ensure they continue to operate the way they do, often at the expense of everyone else.
I recently asked "What would the outcome be of a total taxi ban in a major city" in a similar thread [0]. An interesting answer was the disabled would struggle. I've since discovered Dial-a-Ride [1], which is good to see and now strengthens my convictions against black cabs in London.
For business use alone - public transport just isn’t up to the task without taxis. I know London we’ll for example and can get around for meetings mostly by tube but sometimes a taxi is a must... foreign visitors mainly rely on taxis for meeting appointments
Not disagreeing with your post, but when talking about black cabs and ULEZ we shouldn't forget the historical diesel subsidies:
> The resulting financial incentive for diesel cars helped to prompt a "dash for diesel" after it came into effect in 2001 and was extended in further years. This particularly happened within company car fleets which were responsible for a substantial proportion of new car purchases.
> There are now 12 million diesel cars on Britain's roads, while back in 2000 there were only three million. And in recent years diesels have accounted for around half the new car market, whereas in 2000 only one in seven new cars was a diesel model.
This was a massive 180 by government, which explains some of the exceptions for black cabs.
However, anyone who bought a car after they realised the mistake and repealed it, deserves less sympathy. I wish the ULEZ exception took that into account.
FYI, you can report taxis idling with their engines running to the TfL. I wrote to them last year after regularly seeing waiting taxis idling their engines in front of my workplace, and they wrote back saying it’s unacceptable, and to email them with location, time, registration, and ideally some photo of the taxi.
Although I have seen an improvement in density of taxis idling their engines while waiting, though I now regularly ask normal drivers to turn off their engines when why’re clearly just waiting, often getting angry or hostile reactions.
So many drivers aren’t even aware that they shouldn’t run their engine while parked. At least in most London boroughs idling has become illegal with on-the-spot fines.
Unfortunately the black cab lobby is too powerful for the mayor to do much in my opinion. The slightest change make them go blocking entire streets with their cabs. That's a shame because I still don't understand why they have the privilege to use bus lanes over normal cars.
According to that, max age of a black cab is 15 years. On the plus side, given the age distribution shown, then about 10% of the black cabs will already be 0 emission.
There is already an age limit in place for existing diesel cabs, it is being reduced from 15 to 12 years for earlier models - additionally, TFL will pay up to £10k to delicense caps not built to the latest standards.
Do you have a source for that? Dropping that age limit from 15 to 12 years would obsolete about 20% of the fleet overnight, since the age spread of the cabs is fairly linear.
Really? Myself and most of my friends have never taken a black cab and will never do. We always go for Uber, much cleaner, less expensive and friendly drivers.
I did once. Went less than two miles, and ended up £20 worse off. The other time I tried to use it I got yelled at for getting in it without telling him where I wanted to go.
I do use uber or other private hire in London on occasion - when shifting lots of stuff around, but Black Cabs?
Uber didn't exist 10 years ago, and taxis are still around so clearly Uber hasn't _completely_ wiped them out in that period.
I'm mostly an Uber user now, but even I still end up in a taxi on (very rare) occasions at home and more often when travelling and unable to use Uber or another ridesharing app for some reason.
There's also a decent population of older people who don't use rideshare apps and depend on the taxi system (I write from the perspective of an Australian, not a Londoner, but I'm guessing it may be similar there).
Add to that that then-telephone-only private hire companies are moving to the internet, you're now left with the question of what makes Uber better than another private hire company
Demonstrably false. I have taken an Uber while my friends jumped in a black cab, both going to the exact same destination(because stupidly you cannot order 2 ubers at the same time), and yes, the "base price" for uber was cheaper, but the final bill was a good few quid higher than the black cab.
Which laws? Uber is perfectly legal in the UK, same as Addison Lee. Sure there's lots of complaints from the buggy whip manufacturers, but given their product is
1) Worse to use (standing in the rain with you arm out in the hopes someone will stop, let alone trying to get one on a side street)
2) Based around getting lost (taxi drivers are too arrogant to use technology so will drive into roadworks and traffic jams when modern cars use things like waze or whatever to avoid them)
3) More expensive
4) Less safe (who's driving? Who knows! Lets hope it's not John Worboys)
Given Uber have suppressed investigations into crimes committed by their drivers, point 4 seems overly optimistic.
The fact that Uber hasn't yet broken laws in the UK doesn't make using them more defensible. Would you accept a babysitter that only abused children when on holiday in Thailand?
Undermining unionisation and actively promoting the casualisation of labour in the way they have are to be discouraged whether legal or not.
On the other hand I don't know anyone who does use them.
Uber service is better and cheaper. Why would you ever use a black cab when they're so expensive and often refuse fares or try to scam you by going weird routes?
So you would argue that bus lanes should be HOV lanes - if you have at least 3 people in your car you can use it (although if it's a taxi, minimum would be 4 people)
They are actually hybrids - they have a petrol range extender IIUC
Also, the old terrible diesels still have lots of time left where they are allowed on the road.
Taxis are awful at lining up outside entrances to stations (e.g. kings cross and at pancras) and leave their engines running as they slowly slowly creep forward picking up fares. There are often 20 or 30 diesels basically just idling right outside the main entrance to major stations.
Mentioned this above but taxis are not allowed to idle their engines waiting at taxi stands. You can kindly ask them to turn off their engine (most do without argument).
Or you can also take photographs and report them to the TfL.
As a cyclist, I can tell you that the number of times I see these taxis running on electric only is near zero.
Even if they theoretically get 80 miles of electric only range, and can be plugged in, the reality is the drivers force the engines to run to provide cab heating, avoid downtime while charging, and to avoid wear on the battery.
My guess is in the real world, even excluding manufacturing, these produce more CO2 per mile than the TX4.
Theoretically, even if never plugged in, they should get much better MPG due to the regenerative braking and the ability to always run the combustion engine at the most efficient revs (which for city driving should ~halve fuel consumption alone).
The reality is due to a series of poor design choices, that's rarely the case. Normally due to certifications on the braking system, the regen braking isn't actually hooked up to the brake pedal, so most braking is done with the regular friction brakes. The engine also doesn't normally run at the most efficient RPM because users don't want to hear the sound of the engine revving while they're stationary. Combine that with the fact there are efficiency losses in the battery and electric motors and the added weight of the battery, and you suddenly have a system worse than a regular car.
I've seen these in the Netherlands, nice vehicles. I think a retrofit kit for the old cabs would be nice. Keep the chassis, frame and wheels, swap the engine and tank for a full electric driveline. Given the scale it might be cheaper than new vehicles.
Wondering if those active filters I've seen in the past might be an idea - isn't it the case that exhaust pollution is only half of emissions, with the rest coming from brakes and tyres?
I had in mind that at most 60% of particles emitted by non-electric car are due to the exhaust. It's actually a bit more complex as there are different types of particles with different distributions depending on many factors. In [1], they seem to conclude that it is indeed 50%-50% for most particles, so it would mean that switching to an electric car only halves the emitted particles on the location the car is used (nothing is said about the overall assessment of its lifespan, maintenance, battery recycling, fuel production and transport).
Regarding diesel, it's important to remember that it was a byproduct of oil refinery that had to be used somehow (instead of being discarded and trashed in the nearby river). Some industrial engines and boats have been designed to use it (and are actually better run on diesel engines). Diesel car engine also became a thing, but was originally emitting more small particles. Specific catalytic converters have been introduced to remove those particles decades ago, with very high efficiency (95+%). Those converters are alas not so efficient at lower speed. That's why we don't want too many diesel cars in our cities.
> In [1], they seem to conclude that it is indeed 50%-50% for most particles, so it would mean that switching to an electric car only halves the emitted particles
That isn’t correct, because electric cars mostly use regenerative braking which eliminates brake emissions. Also, this is only for particulates, NOx also emissions are totally eliminated by the switch.
Indeed, I was not aware of it and it makes a huge difference. So local emissions reduction is probably in the 70+% per vehicle. Tyres and roads are the last big chunk of emissions then. Where is my flying Tesla?
Note that this publication only seems to be analyzing the costs post-production. It's important to consider how damaging the cobalt and other rare mineral mining is for the sake of batteries, which are essentially scrap after 10 years or so by current standards. Older ice engines can basically be rebuilt forever as long as they're maintained. Certainly alternative battery technologies will emerge in the future but the current ones seem problematic.
Back in college a few years ago I wrote a paper trying to compare the environmental cost of maintaining and operating 90s cars vs buying and replacing electric car batteries measured by co2 emitted (typically written co2e). This was written around 2012 but I found the break even around 10 years. That is, electric cars were measured as a fairly flat line (not fully flat, assuming some non zero co2e for electricity generation). There was of course a ton of hand waiving but the gas car was assumed to have a y intercept near zero and to be operated for 10 or 15k miles/year (can't remember exactly but I know it was in that range). I would link it but I'm currently not in the same country as the hard drive that might still have a copy of it. Of course I would prefer to have a peer reviewed publication on this, but I had a lot of trouble researching the manufacturing/mining estimates back when I wrote it.
Jeremy Clarkson mentioned a study on Top Gear years ago that showed (as I recall it) that a new Jeep Wrangler would, all things considered, have lower lifetime environmental cost than a new Toyota Prius, the gist of it being that all the high-tech and advanced materials in the Prius had a massive environmental cost that far outweighed its lifetime hydrocarbon frugality when compared to a car as simple to manufacture and being made of basic materials like the Wrangler.
For some reason, people are particularly hostile to countervailing evidence when it contradicts previously swallowed feelgood propaganda.
Edit: 'Using the average CO2 output of the European electricity network, Ernst concluded that an electric car using a 60kWh battery made in Europe would have to travel some 700,000 kilometres (435,000 miles) before it is “greener than an average petrol car”. However, Ernst also says that a fully renewable European grid would reduce the EV’s CO2 lag to just 30,000km (18,640 miles). '
The US wasn't suspicious of Diesel. People here associated them with being too dirty, noisey and high vibration. They didn't want to drive something that ran like a truck or bus. Of course this was in the 70's/80's when there were barely any emission controls and engines were all mechanically controlled. Unfortunately that image stuck with them well into the "clean" diesel era. Shame as my friend had a diesel Passat with manual transmission and it was amazing on fuel and fun to drive.
We learned when VW's diesel cheating scandal came to light that your friend's Passat probably wasn't as clean as the company claimed. It was fun to drive because VW made it run dirty when not on the test stand. This doesn't seem like a good argument for diesel vehicles.
Try following a diesel versus a petrol as a cyclist. There are estimates that the push for diesel is directly responsible for tens of thousands of excess deaths in the UK, for example.
Diesels from 2009 produce 5-10x higher emissions than the regulatory limits when used in real world conditions. Even diesels built this year vastly exceed the required emissions. They actually had to include a fudge factor which they’re slowly decreasing because diesels were so much worse than they were supposed to be.
I don't know how true this is but I've heard the older diesels (2000 era) actually had lower NOx emissions than the newer models due to them running at lower temperatures as they weren't trying to hit newer regulations on particulate emissions.
This also then led to newer models emitting finer particulate which was more easily picked up by the wind and could travel into the lungs more easily instead of denser particulate which fell to the roadside.
This is definitely my experience - breathing diesel exhaust now makes my lungs immediately tighten up in a way that didn't used to happen. Perhaps I'm just getting old though.
Well, at least they have those filters. In Poland, it's common to cut off these filters because most people don't want to spend money to replace them and supposedly the fuel efficiency is better without those.
In the UK there is a £5000 fine for any garage which cuts them out - I wish the same fine was applied in Poland, at the moment it's not legal to do but 1) the penalty for doing so is marginal 2) there is no enforcement at all.
Good. London air is shockingly bad at times. I live much further out with good air and randomly decided to go jogging while in London. Somehow jogging makes the fumes much more noticable
I think the blacksnot is mainly the tube more than anything.
That said it is much better these days than it was perhaps 8-10 years ago in my experience. TfL have started doing some more involved cleaning at night I think - something like magnetic dusting and regular industrial vacuuming to try and control the dust.
Steam trains ran on the Metropolitan and District railways, which have a larger loading gauge. The Northern, and the other deep tubes like the Central and Bakerloo, have always been electric.
The tunnels are also regularly cleaned; I doubt there's much if any Victorian steam train grot still floating around.
Popular methods of representing pollution levels sometimes display data in “equivalent number of cigarettes smoked”, but what about actual cigarette smoke?
There’s an interesting difference between actual pollution levels and what is perceptible. You can’t as easily detect the odour of nitrogen dioxide or micro particles from brakes.
I imagine cigarette smoke accounts for very little pollution measured by typical methods, but walking down a busy street in London you’re likely to pass through dense clouds of it every few meters. I wonder how much difference this concentrated method of delivery makes to the effective toxicity.
This sounds like a perfect place for a hacker piece of art to mount to lamp posts that has air quality sensors and displays some sort of LED art signifying the pollution levels. Skull&crossbones, puking emoji, SARs mask emoji, sunshine & roses, etc.
It is a shame this is not applied to the oldie diesel trains. I often see a 9-carriage train that each has its own engine running idle at a crowded station. Having 15 platforms as at London Bridge Station, provides a decent concentrated dose straight to the lungs.
I've been spending less and less time out during rush hour in my city, and it's gotten to the point that just standing near a car with it's engine running for a few minutes can really make me feel... "off".
Not sick or anything, just a kind of "my body knows that breathing these fumes is not a good thing".
It makes me wonder how I didn't even notice it for so many decades.
But absolutely, we need to get smog out of the places where people spend the majority of their days, if only for an improved quality of life.
As a Chicago resident worried about the terrible air quality here, this gives me some hope that things can be improved if the political will can be mustered.
Glad to hear it has decreased. Nox emissions are mainly from diesel cars which where sold as clean diesel but where dirty. Hopefully hybrid and electric vehicles will decrease air pollution a lot more. Also car free city centers are a real possibility.
Heathrow has higher flight density, no 3rd runway.
The real issue is that they put east-west airport runways due east/west of the centroid of population. It’s almost as if they wanted the airports to maximally affect as many Londoners as possible.
This is something I don't understand. There must be a sane reason, right?
I mean, they can't be so bloody stupid to have put the biggest airport in Europe on the western outskirts of a city and then have made a major landing strip come in from the east.
To your point, airplanes coming in basically bathe the entire city east to west in noise.
Why this is only applied to the very central of London? (Even the Tower Bridge is not covered.) Why is it allowed to pollute the streets where people actually live?
> Polluting vehicles account for around half of London’s harmful NOx air emissions, with air pollution costing the capital up to £3.7 billion every year
So there's less pollution in the zone, but do we know whether it's simply moved to outside the zone? We want to have less pollution, not just spread out pollution.
Breakdowns of petroleum use generally split between transport, commercial/residential, and industrial uses.
NOx generally result from very high-temperature combustion -- sources such as building heat and cooking hobs won't contribute so much (though they can produce considerable net CO2 emissions, soot, and VOCs). Stationary powerplants (construction equipment, generators, compressors, pumps), and and industrial processes, typically account for much.
Landscaping equipment, especially two-cycle engines, are especially polluting due to incomplete combustion.
Quite often going into Liverpool St I used to see pals of smoke from fires, and whilst an occasional occurrence they’re not rare, I would have thought across the whole of London they’d add quite a bit.
Construction machinery, Busses, Gas heating boilers? Probably not trains, only a few long distance trains out of Paddington and St Pancras are still diesel powered.
Sleeper to Cornwall is the one I often see but the rest is all electric for the Paddington bit - of course trains going West switch to diesel once they get off the electrified line e.g. at Swindon for Cheltenham
There's diesel trains running out of Kings Cross, Euston, Marylebone and Waterloo as well. They're definitely the minority of train services overall, but there's still a lot of them.
I used to walk alongside Euston to go to work. The air quality was noticeably bad, and you could feel the heat from the consistently running Diesel engines. It’s upsetting they don’t power down while parked.
Yeah, and they're probably going to be doing that for quite a while longer after the Government killed off plans for rail electrification on most of the currently-unelectrified parts of the network.
Would it be possible to shut off the engine when entering the peripheral of London and coast into the station with zero emissions? Perhaps use an electric locomotive to push or pull them out of London, again with zero (local) emissions.
Trains into London are being gradually replaced with electrics and hybrids - see the Class 800/801/802 ("IET", "Azuma"). These will use diesel nowhere near London.
Dragging trains into/out of London with an electric loco would pretty much kill the frequency of the lines. This isn't the US where we might get five long-distance passenger trains a day - London King's Cross and Euston are busy, with service patterns at breaking point as it is. There's nowhere outside the city where trains could stop and wait for a locomotive, anyway.
Diesel trains built in the last two decades (e.g. class 220/221/222) are already Diesel-electric, meaning the Diesel engine drives a generator which powers an electric motor. Doing it this way is more effective because you can run the Diesel engine under optimal conditions all the time.
This also makes it possible to build bi-modal trains that run on Diesel on non-electrified tracks and use a pantograph on electrified bits (like London). That's what is being done in the UK now under the Intercity Express programme in order to replace the old Diesel trains (HST/Class 125): https://www.hitachi-rail.com/products/rolling_stock/bi_mode/... - these are the class 800/801/802 trains mentioned by vertex-four in a sibling comment.
The trouble with this is that the trains have to have both a full set of diesel generation equipment for non-electrified operation and a full set of power conversion equipment for electrified mode, plus some way of switching between the two. The class 800 doesn't seem to have done a terribly great job of this; there's been huge teething problems with their introduction and rumour has it that the underfloor diesel engines simply can't operate at outside temperatures above 30 C or so due to inadequate cooling in order to fit them into the space available.
The 800's west out of Paddington don't seem too bad
I regularly get the Cheltenham to Paddington train, and apart from the slight extra delay at Swindon while they switch power haven't had any problems with them.
Some of the early seat covers are being replaced because they don't wear well though
With purely diesel trains - No, it wouldn't. There's still quite a bit of friction, plus there are turns (= even more friction to apply the turning force).
Only if it's a diesel/electric, but then you're not really turning off the engine.
Work from Oslo has shown that building machinery is a major source of carbon emissions and NOx in cities. I would also expect buses to be a major source if they are not included in the numbers above.
Going all electric is all good and we’ll but it in effect just pushing the pollution out somewhere else... that issue still has to be solved. Electricity doesn’t grow on trees
1. breathing polluted air sucks, and we can improve that by replacing gas vehicles with electric vehicles.
2. global warming is awful, and we can improve that by replacing our generation activity (solar, wind, hydro, nuclear) -- but if we replace it all and there's still lots of gas cars on the road, we've still got a problem.
Electric cars are part of solving both problems, although in all honesty, we probably need to accept a lower standard of living, ditching the private car, switch to e-bikes, e-scooters et all and have a robust car hire scheme for when vehicles are necessary,
Incidentally I got a proposal to vote on the other day proposing changing Park Lane southbound into park land with cafes which I think would be nice. (https://www.westminster.gov.uk/sites/default/files/mayfair_n... p32)