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Coventry Very Light Rail
33 Kaibeezy 52 6/7/2025, 9:35:44 PM coventry.gov.uk ↗
> The vehicle is battery-powered, eliminating the need for overhead wires. It features an innovative turning system, enabling it to handle 15m radius curves. This allows for installation in tight corners within the existing highway. The Council intends for it to operate at a high frequency, providing a turn-up-and-go service. The vehicle has a capacity of 56, is comfortable and has low floors to enable passengers to embark and disembark easily. The vehicle has been developed to allow autonomous operation in future.
> The new track is laid just 30cm within the road’s surface, minimising the need to relocate pipes and cables, which is time-consuming and expensive. It achieves this by leveraging cutting-edge materials science, while still utilising standard rail parts to ensure ease of manufacture.
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?
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.
They make all kinds of claims that don't stand up to over 100 years of history running trains. The claim they are innovative, but there is nothing new here, and no evidence they have looked at the real problems of transit systems. Someone is going to make a lot of money on this at the expense of the community that loses.
Trains have been around for a long time. You can buy all the parts you need for a good system off the shelf. You won't be saving money by designing something new, you just waste money on engineers to design something and then lose the scale factors you could get from buying the same thing as everyone else. If you buy the same thing as everyone else that means there will be a market for spare parts and thus in 20 years when (not if!) something breaks you can keep the system running.
Yes overhead wires are expensive - but they are a rounding error compared to track. Batteries are expensive too, and you have to buy a lot of them. Batteries need to be recharged which means these trams will be out of service often so they have to buy a lot more so that when one is out of service for charging the others can work. (you still need a few extra for maintenance, but battery charging is more common so you need a lot more)
If you want to build a train the best way to save money is to build exactly the same as everyone else does: standard off the shelf trains, running on standard off the shelf rails, and standard off the shelf overhead rail. If you want to innovate make sure that everyone is fluent in Spanish, Turkish, Korean, or Italian - because places where those languages are spoke build and run trains much cheaper than other places you can think of so you want to learn from them. (note that French or Japanese are not on the above list - while those areas do cheaper than English speakers, they are still expensive)
I'm not sure about the UK, but in the US most of the cost blowout for trains seems to be in stations, so focus all your innovation there: don't make them monuments to how much money you can spend. (The UK has cost problems almost as bad as the US, but I'm not aware of any study on where the issues come from, while at least in the US there are studies).
Anyway everyone is pretty sure that that something is wrong with the standard train economics as you describe them, because if there wasn't something wrong with it there'd be a lot more trains. I can't tell from the site, or from your comment, if this is the solution, or even worth doing as an experiment... but "don't change anything ever" doesn't strike me as productive either.
Innovation should require some knowlegde of what is already done - otherwise you invent square wheels.
I agree with much of your sentiment, and hope that the Coventry council is being challenged in these sorts of ways, but at the same time I recognise that each city is going to have quite different requirements for trams driving down the roads in its centre.
Perhaps a better push back is: why isn’t this just a better bus network?
There are different modes of operation that differentiate them but fundamentaly they are all trains and face the same issues
Eliminating overhead wires isn’t about cost. It’s about being able to build in existing urban areas that don’t want high voltage live wires everywhere, and likely already have above ground infrastructure they would interfere with.
The fact that buses are so flexible and easily (and cheaply) rerouted makes developers less likely to build developments that rely on access to transit, but once a community spends a hundreds of millions of dollars on a light rail line, they know it's there for the long term.
Modern urban light rail is also typically electric, using overhead power. Although buses can also use this.
This is one of the main reasons the super dense Japanese cities aren't as air poluted as other urban centers.
Not really that efficient...
And, as has been rediscovered about 200 times in Southern California (by the drivers, not by the sstate government), you can add additional lanes almost indefinitely, and it doesn't really help congestion that much.
Busses aren't much more efficient when riding down a lane than lower occupancy vehicles, but streets aren't bottlenecked by their roads, they're bottlenecked by their intersections. The key advantage of a bus is at the intersection. A bus holds the intersection for far less time than the equivalent passenger capacity of cars.
The problem bus lanes try to solve is dominantly that without them the traffic advantage of people riding busses mostly goes to people not riding busses, and this makes for a pretty terrible incentive structure. Busses are intrinsically disadvantaged against cars (schedules, uncertainty, routes), so if you don't help them, then people will prefer to drive. Bus lanes internalize the externality.
And your bus only lane has a lot more options. If there is a major disaster you can divert other traffic (not necessarily all traffic though that is an option) into it which might be a useful compromise at time. If you need to repair your bus only lane you just divert the bus to regular traffic. For that matter most places there isn't any traffic and so a bus in mixed traffic has no downsides thus not costing you that whole lane (or track), just build the bus-only lane where it is needed.
Trains are a good thing when they do something a road cannot. However the common bus can be just as good for much less. If you have the money and want good service and ride quality the bus can do it too, and typically for much less cost than a train.
Trains are good where they don't mix with traffic (meaning elevated or underground) because they can then be automated (and also faster). Alternatively a train can hold more people, so if you are in the rare situation where a 100 passenger bus every 5 minutes can't handle the passengers a train is good. Most of the time though you are not in either situation and so a bus can do everything a train can.
A rail track for the same route sits empty just as much.
> you can add additional lanes almost indefinitely, and it doesn't really help congestion that much.
I don't think adding bus-only lanes would have that effect. Adding lanes for private vehicles reduces congestion, which encourages people to move to places along the route until the congestion reaches the previous barely-tolerable level (as I understand it).
While that bus lane may look empty most of the time it likely carries far more people per hour than the congested car lane next to it.
> While the Lincoln Tunnel’s car lane can only move 3,000 people per hour in each car lane, its bus lane moves 30,000 people per hour.
https://transalt.org/blog/bus-commutes-are-significantly-lon...
You can make the same argument (in terms of space) about a train track. The real advantage of trains (light or heavy) is permanence. It's easy for the next government to remove the bus lanes because "OMG too much traffic, one more lane will fix it." It's much more difficult to rip out a rail line and convert it to a road.
Other advantages: people who don't drive, which includes children can get about. Lots of public transport can compensate alot for un walkability of suburbia.
Getting 1000 people downtown could be up to 2,000 Waymo trips (one trip to drop off the worker, another trip for the car to go back out to pick up another passenger). While one of these 56 passenger very light rail cars can do it in 18 trips. A light rail vehicle like the Siemens trains used in San Francisco can carry up to 200 people at crush loads, so that's 5 trips.
* Think having much higher speed limits (as far as humans are concerned, nonexistent), or mass coordinating movement over the entire traffic.
** We can reasonably estimate the minimum without bothering to ask how fast the tech will improve: Even if the tech were available now, think about fleet replacement costs which no one group would be too eager to pay. Best case, it's the typical 'make a concentrated pressure group lose for societal benefit' and we know how that politics goes. It will happen, but slowly.
*** Another thing to account for is that there's no good reason to design an AV car like a normal car, and there'll be some iteration time over that too.
[1]: https://data.transportation.gov/Public-Transit/2022-2023-NTD...
I don’t think fixed route transport infrastructure is going to have trouble competing on efficiency.
They were targeting $7.5k for their in house honeycomb lidars and they have 12 of them - that’s 90k already.
https://www.theverge.com/2021/8/27/22644370/waymo-lidar-stop...
They also aren’t close to the $7.5k target (there isn’t any public source for that so you’ll have to take my word for it).
Also $30k wouldn’t even cover the base vehicle.
The price is somewhat of a guess, several years ago, the hardware in Waymo was priced at $130k by Munro&Associates. But since then the cost of the LIDAR sensors fell by 90% or so, reducing the main expense.
And Baidu has cars on the road that cost $30k for the _entire_ car. So presumably, so even a couple of pricier sensors won't affect the estimate too much.
Waymo uses brand-new electric Jaguars.
But there is no _reason_ to use Jaguars and not specially-built smaller and less powerful cars, when Waymo finally starts a real rollout.
I'm not including the base vehicle in the cost. It's highly variable, and can be as low as $10k for small personal intra-city taxis.
China has already launched a $30k taxi: https://www.forbes.com/sites/bradtempleton/2024/05/14/baidu-...
This _completely_ blows any transit out of the competition. Literally nothing can come even close in the end-to-end efficiency.