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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 wor
by jsnell 1y ago
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?
- bluGill 1y agoTiny 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)
- bardak 1y agoYeah but you could do that with a bus today without miltiions in infrastructure spending
- scott_w 1y agoNot 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.
- vidarh 1y agoTrams very often still share the road with cars.
- jonwinstanley 1y agoThe 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.
- scott_w 1y agoNot for all of the route, typically. Metrolink only in the city centre then it turns into a Metro line for the rest of the commuter route.
- vidarh 1y agoQuite 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.
- scott_w 1y agoI 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.
- speleding 1y agoThe 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.
- jsnell 1y agoI 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.
- bluGill 1y agoA bus cannot be run ever two minutes. No amount of dispatch anywhere has pulled that off. I'm not sure if a tram can be run that often but subways are
- grues-dinner 1y agoBus 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.
- chgs 1y agoWhat single BRT line runs at that capacity?
- dantastic 1y agoProbably 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. [0]: https://brtdata.org/location/latin_america/brazil/rio_de_janeiro https://brtdata.org/location/latin_america/brazil/rio_de_jan...
- ehnto 1y agoThat 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.
- deleted 1y ago[deleted]
- Veedrac 1y agoTrams 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.
- laurencerowe 1y agoThose 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.)
- scott_w 1y agoAbsolutely! 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!
- laurencerowe 1y agoMuch 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.
- rjsw 1y agoThe line out to the airport isn't using an old rail line and is fairly slow.
- ehnto 1y agoI think the up front investment is quite literally the problem this is solving for. If it weren't, you would just use light rail. The ability for the tracks to be laid so shallow is in my view, the entire innovation and cost is the reason for this approach.
- pantalaimon 1y agoIf higher capacity is needed you can always link multiple units together
- closewith 1y agoIn CVLR, you actually cannot as the extreme bogey angles mean they can only operate individually. You also can't order longer cars. You can run them at high frequency though.
- mhandley 1y agoWith 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.
- closewith 1y agoI 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.
- mhandley 1y agoIf 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.
- analog31 1y agoLinking 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.
- brnt 1y agoBuses 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.
- youngtaff 1y agoHave 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
- James_K 1y agoI'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.)
- chgs 1y agoTrans 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.
- IshKebab 1y agoTrams 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.
- hgomersall 1y agoTrams 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).
- IshKebab 1y agoI agree, but I don't think that really matters. I mean nobody is going to spend millions on a tram just because it's a bit smoother. It's a nice bonus; not a reason to build trams.
- hgomersall 1y agoOn 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.
- Simon_O_Rourke 1y agoThis 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.
- JdeBP 1y agoIn many non-North American cities one needs tiny. Big stuff just does not fit.
- imtringued 1y agoA normal public transit bus has twice the seats and doesn't need rails.
- JdeBP 1y agoYes and no. 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 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.
- ericmay 1y agoIn 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.
- JSR_FDED 1y agoI guess you don’t need much space to dip your baguette in a cuppa tea
- jeroenhd 1y agoTrams 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.
- notahacker 1y agoGenerally 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.
- JdeBP 1y agoSee https://news.ycombinator.com/item?id=44217164 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.
- deleted 1y ago[deleted]
- switknee 1y agoBuses 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
- stephen_g 1y agoAlso 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.
- noodlesUK 1y agoInterestingly 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.