These things are tiny! I've traveled in larger airport shuttles.
It feels like that's putting this into a really awkward place in the tradeoff space. Trams work because they can scale higher than buses. That scale comes at the cost of more up-front infrastructure, much less flexibility, and needing dedicated lanes. So cities don't have trams everywhere, but they're only installed on routes that can support the scale.
For these you still have the up-front investment (just less of it) and inflexibility, but don't get the efficiencies of scale due to how small the capacity is.
Is this really just a bet that they can get autonomous tram-driving on city street approved a decade+ sooner than autonomous buses?
Trans don’t need dedicated lanes, not sure where you got that idea from. Trains do.
Buses however are slow (in London about the same as walking) and (outside London) prone to vanishing on timetable changes. Closing a rail link is tricky, you can be confident that if you live near a tram stop it will be there in 10 years. 60% of our local (say 10 mile radius) buses have been removed in the last decade, removing entire villages from service.
A rail solution allows you to read, a bus throws you around everywhere and makes you sick.
Buses are considerably faster than walking, no? Eg 8 to 9mph or about 13kph in London on average[0].
I also observe that this is an average speed, which night be useful for statistical summarization but is not as useful as knowing whether the portion of the route that you want to take is in the faster part or the slower part of the data readings.
For example, if I took a bus from Aldwych up Holborn to Euston I might expect that the first mile would indeed be walking pace but the second mile I would be zipping along. It's important as a bus rider to not let the slow parts color your perception of the whole ride.
Whenever I've taken a bus in London it tends to be in zone 1. Between the walking to the right stop, waiting for the bus, the traffic, then walking at the far end, it's rarely quicker than walking.
Last week for example I took a bus from near St Pauls to Trafalgar Square, the entire jouney took about half an hour for 1.5 miles.
I usually take the tube in London but there are some point to points where bus is clearly faster than tube connections would be and absolutely faster than walking. Don't really know Manhattan up that far but crosstown tends to be slow in general.
Buses also put a lot of weight on the road surface. Even more if you fill the bus with batteries. If you can reduce road surface wear at a cost of an upfront investment in installing these rails that could be a good trade off.
>A rail solution allows you to read, a bus throws you around everywhere and makes you sick.
I got exactly the opposite impression the first time I rode a tram in my life. The tram is really really shaky and the connection with the overhead line is flaky, leading to all sorts of strange noises.
My experience has been the opposite: every vehicle on rails has offered a superior ride quality to every vehicle on rubber tires. I can't read on a bus, but on a train it's no problem.
Buses meant for right-hand drive markets like the UK, Australia and Japan are (with very few exceptions) shaky, low-entry configuration two door junk, or double-decker one door junk.
If that's what you're used to, even the most rickety light rail system will feel luxurious by comparison.
Left-hand drive low-floor buses with three doors, and articulated models with four doors, which are intended for the European market, are as a general rule much more comfortable. If the buses you normally take fit the latter description, you'll probably find the average tram worse.
Trams can be removed too. Bristol used to have trams. I doubt it is alone.
I definitely feel like trams are a weird technical solution to a policy/perception problem. On a technical level I don't think there's that much to recommend them over buses with bus lanes. It's just that governments never put bus lanes the whole way like you are forced to do with a tram.
Trams are much smoother than buses. I suspect that a bus can be made as comfortable as a tram with active suspension optimising ride quality, but I've never come across one. Jerky starts and stops, swinging around, kneeling for (dis)embarkation; these all make the ride unpleasant for users. Trams exclude those at the cost of additional up front infrastructure costs.
I can easily read a book on a tram. No chance on a bus (unless we want vomit all over the seats).
On the contrary, it's the reason we should build more trams. If the objective is to have more people using public transport, then we need to make them as nice as possible for people to use. Comfort is the user facing benefit of trams.
Passenger UX:
- railed vehicles only move and accelerate longitudinally (with a little centripetal force at the very predictable corners). Consequences: people will often choose to stand even while there are free seats. Trams are so smooth that standing feels comfortable. (If you preference is to sit, you benefit too.)
- modern trams have lower floors than any road vehicle can realistically achieve (especially if built for use on random roads). They're near flush with the curb at tram stops, which is nice for accessibility (prams, wheelchairs, people with granny-trolleys for shopping).
Pedestrian UX:
- trams follow tram paths, predictably. Once you're used to them (which doesn't take long), you'll stand just centimeters from a passing tram and feel completely comfortable about it. As a pedestrian, no transit line is as easy to cross as a tram line. (Certainly not a bus lane!)
Land use:
- since trams follow rails without any lateral deviation or wiggle (and bonus: they're rather narrow), dedicated tram lines require about 40% less land than bus lanes. Especially on streets where there might not be much free lane width to spare, that counts!
Tiny operating costs, negligible marginal costs:
- there's a far higher ratio of passengers to driver in a tram
- electricity over wire makes the marginal cost of energy to operate negligible.
Once the infrastructure is there, and once the tram is running, the frequency of service can be increased and the operating cost can get arbitrarily cheap.
Transit capacity:
- road intersections are the capacity bottleneck in any road grid. Behind them, queues form and grow (congestion) until a point where the expected time (much of it queuing in traffic) presents too high a cost for the marginal journey to happen.
- trams can pass at same gauge while scaling up intersection capacity by about two orders of magnitude, allowing much more rapid movement of people with much less urban land and less infrastructure
(buses with dedicated lanes could hypothetically deliver this, if buses were as popular as trams and operated like trams in dedicated lanes)
Air pollution:
- the primary source of most urban air pollution is road vehicle abrasion (tyres on roads, brake dust) and road vehicle combustion engines. Getting rid of combustion engines solves less than half that problem. To stop primary emission of particulates, you need to solve tyres and car brakes. Railed vehicles do that: clean air.
- a large part of air pollution is secondary: particulates settle on the large road surfaces comprising much of our cities. Then road vehicles with large tyre surface area (and varying lateral positions) run over the surface, re-ejecting that dust up into the air.
That air pollution is killing people (estimates vary: somewhere from 'many months' to 'a few years' of life expectancy are lost to urban air pollution). Trams get rid of it completely.
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The biggest problem with trams is that they require competent civic administration, with a steady pace of long term infrastructure investment (boom & bust would destroys the capacity to produce & maintain trams & infrastructure economically), financed at competitive rates. They also benefit from very high urban walkability in the vicinity of potential tram stops, and high density of development (including housing). Not many cities have that.
Tiny might make sense if they are running every 2 minutes and thus getting their capacity via frequency. However there is no reason to think they will do that. (if they were running anywhere near that frequent overhead wire would be a lot cheaper than a battery on every tram)
The main operating cost of running a bus line is the salary of the bus driver. It dwarfs vehicle maintenance cost and petrol. The VLR has the ambition to run autonomously eventually. Autonomous buses are quite a bit further into the future.
Not really because buses get stuck in traffic all the time because there’s a point where they need to share roads with cars. Once you spend the money on segregating buses entirely, you’re at the same level as the tram line.
Also, because of the expensive infrastructure that can only be used by trams, there’s a permanence there that prevents future politicians from ripping it out to put more cars on for a quick political win with drivers.
Going back to point 1: having a line means that any route needs to be properly planned because you never have an escape hatch of “just stick them on the road.” Example: where I live, the council installed a bus lane and a cycle lane. Where it pinches in (planning fuck up), it dumps all the traffic into a shared route with 2 roundabouts and 5 exits, each with an insane amount of traffic coming to or from them. Buses that are forced to use that route are always late. It takes me just as long to drive as it does to take the bus, faster if you factor in me waiting for a late bus.
The solution to that is dedicated bus lanes, which are quite common in some cities. Usually they allow taxis and emergency vehicles as well.
Trams here in Berlin share the street with the cars on some streets. So, it's exactly like a bus that can get stuck in traffic (and they do). Dedicated tracks are also common but they take up a lot of space and it's expensive infrastructure to install. Mostly trams are limited to the former East Berlin, though they've started to spread to some parts on the west side.
With electrical buses and bus lanes, you get most of the advantages of trams. There are probably still some advantages to dedicated tram lines. But they are expensive to install. I'm not sure it's worth the investment.
> Also, because of the expensive infrastructure that can only be used by trams, there’s a permanence there that prevents future politicians from ripping it out to put more cars on for a quick political win with drivers.
A few things to further this:
- I’ve seen bus lanes get ripped out and moved around, you can see where the paint was cut off.
- Taxis use bus lanes, usually.
- People use bus lanes illegally if they’re not enforced with cameras (political cost of installing the cameras).
> Also, because of the expensive infrastructure that can only be used by trams, there’s a permanence there that prevents future politicians from ripping it out to put more cars on for a quick political win with drivers.
This is definitively not true. It's something people said about the Washington, DC streetcar and it turns out they are about to remove the streetcar in order to replace it with buses:
I would have hoped it was clear that I never stated infrastructure was never ripped out, since there have been numerous examples of this happening, including my own home city. I’m merely making the point that tearing up tram lines is more costly than simply paying someone to cut paint lines off the road. That plus the initial investment creates an inertia against undoing it, though nothing prevents politicians pissing public money up the wall if they’re determined enough.
The Nottingham tram, not far from Coventry, usually only shares road with cars in the city centre which is mostly pedestrianised. So mostly avoids commute traffic.
Quite a few do, and the point remains that sharing or not sharing the space with cars isn't a feature that distinguishes trams from buses. You'll can - and do - have dedicated rights of way for both, and you can - and do - share routes with cares for both.
I know of no bus routes that completely separate from cars beyond a strip of paint. I also know of no countries that give buses automatic priority over cars outside of bus lanes.
> Not really because buses get stuck in traffic all the time because there’s a point where they need to share roads with cars.
Like many tram lines, CVLR is being laid in-road and not segregated. In fact, while not mentioned here, the it's 15 m turning radius is so important is because it's planned to traverse roundabouts in-lane.
I didn't really mean that they needed higher capacity. If they had the passenger volume to justify such high intervals, they'd already have real trams.
But rather, this is giving up the benefit trams have over buses, without gaining any new edge to replace it. So why is it a good tradeoff? And why now, not 20 years ago?
The autonomous driving angle is the only idea I have.
Bus Rapid Transits can operate at frequencies of about 10 seconds per bus. Obviously they're highly parallelised to achieve that and have special infrastructure to enable it like dedicated stations and pedestrian access, so it's not just "a bus", but bus-based systems are how many of the very highest-throughput public transportation lines function, with up to 35000 people per hour per direction with three digit numbers of buses per hour.
For comparison, the most frequent London underground service is 100 seconds per train and the system moves about 50k passengers an hour (based on a 21% increase representing 10k passengers, I couldn't find a direct figure), presumably that being both directions.
Probably the Rio de Janeiro one. The BRS Presidente Vargas corridor has a peak frequency of 600/hour, according to this site [0]. Pretty impressive IMHO.
BRTs corridors often have dedicated stations with passing/bypass lanes and dedicated pedestrian access, but in the same way that subways and light rail are just a ton of trains down the same track, pretty much.
I don’t know if two minutes are possible, but in Berne, Switzerland, the bus line 10 runs every three minutes. Parts of the loop have dedicated bus lanes, but it‘s probably less than a third of the distance.
That is in the article. The intention is a frequent, arrive and go service. Maybe every 2, 5, 10 minutes, whatever the actual details will be, that is the goal.
I'd assumed the point of them was that you can take the several cars of a tram and split them up to have more frequent services. Though I suppose this would compound with the cost of having a driver on each car, potentially cancelling some of the gains from cheap installation. As for the point of automation, I think the tram can probably be a lot easier than the bus because of the human factor. It seems safer, so legislators will be more willing to legalise it and residents less likely to complain. Also, you've got rails in the road that clearly mark the route of the tram which make it more visible than an automated bus. Most of these automated taxi companies still have a human supervising the process, and I imagine that could be employed here to good effect and with fewer or faster manual interventions than would otherwise be needed.
Even if all that falls through, I'm not gonna complain about it. We sorely need more public infrastructure in the UK. Even if an experiment like this fails, at least you actually get a tram line and experience out of it. Much better than a project which sucks up million then gets cancelled. (Cough cough HS2.)
Buses on dedicated lanes are OK indeed. However, buses are simply not as comfortable as trams: roads unless in tiptop shape are not as smooth as rail, and bus drivers always take corners too fast.
Having to hold on to something discards it from my preferred list of solutions.
Trams can share lanes with normal car traffic. There's still a massive cost in terms of infrastructure (especially the overhead lines, utilities that need to get out of the way for the rail base, that sort of thing), but this project has a detailed description of why those aren't a problem for this project.
The tram they show in the animation also very much has a driver in the front.
If they can deliver on what they show in their demos, I don't see why the size of the trams or the infrastructure should be a problem. All the expensive stuff has been thought about, the system barely takes up any extra space, and the system is capable of scaling up by just sending more vehicles into service.
Generally I'm in favour of this sort of project, but having lived in Coventry (albeit a while ago) I'm a little sceptical: it's basically just adding a lot of infrastructure cost to what were low frequency suburban bus routes (the actual centre of Coventry is compact and walkable). You can run regular buses with similar capacity on batteries too, and divert them more easily.
See https://news.ycombinator.com/item?id=44217164 . Coventry actually does, right now, run quite an extensive network of electric regular buses, not only out of Pool Meadow but also the ones that circle the Trinity Street/Burges loop. And they had to divert them to build the demonstrator track for this.
Trams don't actually scale higher than busses; the highest ridership BRTs have far more ridership than the highest ridership light rail. The key thing that makes it work is having a dedicated right of way. I expect busses get a bad rap as a scaled transit solution mostly because they have to share the roads so often. But it's indeed an advantage of light rail that it's a lot harder to make that mistake with it.
Those BRTs will have lower passenger/operator ratios though since trams tend to be bigger than articulated buses and are frequently coupled together for busier routes.
I definitely agree that the dedicated right of way is the main thing. It's why some of San Francisco's trams are so slow outside of the city centre (where they run in a tunnel) and why Manchester's trams are so slow through the city centre (where they run at surface level sharing the street with pedestrians.)
Absolutely! I’ve used the Manchester Metrolink and it definitely slows down in the city centre. It does speed up a lot (and likely beats bus in rush hour) when you’re off the streets, which makes it an incredible commuter option!
Much of it is built on repurposed heavy rail lines and those sections are great. The Eccles Line through Salford Quays is horribly slow and windy though which was a pain for commuting to Media City from south east Manchester.
I believe the new Trafford line improves things somewhat but Manchester really needs much more heavy rail capacity.
With computerized control and a comms link between the vehicles, you could probably have one vehicle follow 1m behind another, so they are effectively a train. If you still have a driver at all, you only need one in the front vehicle.
I don't think you could do that for CVLR specifically as it's not segregated from traffic and the second car would have to react individually to vehicles, pedestrians, roundabouts, etc.
If it's really just 1m behind, it doesn't need to respond individually to anything except pedestrians. And you can solve that with some extensible tapes that actually do connect the vehicles to prevent pedestrians walking between them.
Linking multiple units means making the stations longer. A more likely scenario is to deploy more units and deal with staffing by migrating to autonomous operation.
Buses have slightly lower capex but much higher opex from the perspective of the community. City street gets ripped up by buses, cyclists get caught under the bus and dragged for miles, children get asthma from the tire dust. It being easier to give trams priority at traffic lights and easier to make the tram autonomous are just added bonuses.
Lower flexibility is actually a feature when it comes to mass transit: People will build density along rail lines because they assume the town won't rip them up, making the rail line more valuable over time. A bus route can be cancelled the day after a disruptive mayor is voted into office.
I also don't see why you can't scale up the tram with additional cars, as long as you keep the lbs/sqft the same. 3 car trams are fine, 3 car busses are... not
Also higher OPEX from the operator's point of view - trams can carry a lot more passengers per driver, they're more efficient energy-wise, and the replacement cost for bus tyres is large compared to steel wheels that last way longer.
Interestingly in this case the tram fits far fewer people than a typical British bus. A modern London route master fits a maximum of 87 people (standing and seated). This tram only fits 50 (standing and seated). I'm nonetheless certain that it will be a much nicer way to travel, but I'm not sure that the maths work out the way you might initially expect.
Have recently read Gareth Dennis’ How Railways will fix the Future…
It’s a worthwhile read BTW
I suspect these are too small to carry a significant number of passengers per hour
They’ll also probably never be autonomous as the challenge with autonomous is less the driving and more with passengers getting on and off, getting trapped etc
This is such a typical American sneer at public transport.
It's tiny, how it possibly carry all those 2x4s, powertools and sheets of plywood when I'm out doing manly things. I'd better go buy that monster truck so I can look like a real man.
This is a) an unnecessary counter-sneer at two whole continents and b) dismissive of something that would be a real problem in a city bigger than Coventry.
Those teeny tiny little carriages have a capacity a quarter of what the trams in my city provide. If one of them pulled up in peak hour here, I imagine it would fill up after two stops and be a nuisance from there on.
Yes, this is smaller than the double-deckers in Coventry, that you can even do an eyeball comparison with if you watch the ironic publicity video mentioned in https://news.ycombinator.com/item?id=44217231 and keep your eyes peeled for the buses queued up at those temporary traffic lights in the background.
No, it's roughly on a par with the single-deckers, though, and there are quite a lot of those used by the local bus operators.
In the US a bus is a strictly worse version of the private car. Walking/biking/rail are effectively category differences so they don’t compete on the same playing field as a car and bus will. It’s very important for public transportation officials in particular to understand this, because not understanding it will continue the car-only suburban development until we run out of money and economic physics dictates how we do transportation but with insane costs in the meanwhile.
Amusingly for this stereotyping, the demonstrator that they have constructed has a Burger King a short walk to the south and two Chinese restaurants and one Indian a short walk to the north. (-:
It feels like that's putting this into a really awkward place in the tradeoff space. Trams work because they can scale higher than buses. That scale comes at the cost of more up-front infrastructure, much less flexibility, and needing dedicated lanes. So cities don't have trams everywhere, but they're only installed on routes that can support the scale.
For these you still have the up-front investment (just less of it) and inflexibility, but don't get the efficiencies of scale due to how small the capacity is.
Is this really just a bet that they can get autonomous tram-driving on city street approved a decade+ sooner than autonomous buses?