[HN Gopher] Why we stopped building cut and cover
___________________________________________________________________
Why we stopped building cut and cover
Author : jseliger
Score : 161 points
Date : 2024-02-16 16:04 UTC (6 hours ago)
(HTM) web link (worksinprogress.co)
(TXT) w3m dump (worksinprogress.co)
| mc32 wrote:
| As far as I understand it, and this may be outdated, cut and
| cover is way cheaper than boring. And you only bored tunnels if
| you had no other choice --like Big Bertha in Seattle. BaRT was
| mostly cut and cover as obviated by going under Market and
| Mission streets.
|
| Maybe new boring machines are faster and cheaper and break down
| less than before.
| gumby wrote:
| Yes, cut and cover is cheaper to execute than using a boring
| machine in most cases _and when possible_.
|
| But the externalities of cut and cover can be very expensive
| (blocks streets, and hurts nearby businessen even to the point
| of going out of business). Those second order effects, even if
| transient on a long term scale, can cause expensive hold ups.
| Other externalities are the need to get around existing
| infrastructure, some of which could have over a century of
| continuous use.
|
| So for example in NY it is _almost_ impossible (look at the 2nd
| ave subway, which is mostly pretty shallow) while in LA cut and
| cover was no problem at all.
| BobaFloutist wrote:
| I wonder if the price difference between boring and cut and
| cover is greater than the cost to just...cover business's
| expenses (rent, loan interest, payroll) for the time it takes
| to get cut and cover done on that block. Could we just pay
| them off?
| actionfromafar wrote:
| That sounds like it could be cost effective if one only
| includes the individual businesses and cover their losses,
| but it can still cause second order effect harm, like
| customers changing habits and not returning to the original
| place. Something to think about. Suboptimal infrastructure
| is also costly, of course...
| BobaFloutist wrote:
| Honestly I'd be fine with it if the public agencies just
| used it as a justification for a eminent-domain style
| "We're going to do this project this way in the interest
| of the public, we're giving you some cash to cover your
| immediate costs, and that's that."
| immibis wrote:
| The justification for business owners making profits is
| that it's payment for taking risks. Why then are we
| trying to shield them from risks while still allowing
| them to make profits?
| bluGill wrote:
| Because we want business to take those risks. In the end
| I benefit from those businesses - not all of them, but
| some of them.
|
| Businesses should take risks. However government should
| not add extra risk without careful consideration.
| samatman wrote:
| Business owners making profit needs no justification,
| that's entirely backward. Anywhere there are people,
| there are goods for sale. The ones who need to justify
| themselves are the ones who propose to restrict this. It
| can be done, I consider the restrictions on the nuclear
| weapons and slave markets eminently justifiable. But in a
| free society, the default is freedom.
| gumby wrote:
| For private sector projects people do get bought off (in a
| non-corrupt sense of that phrase) but that seems to be
| unacceptable for public projects for some reason.
|
| I'm talking about the US here -- no idea elsewhere.
| BobaFloutist wrote:
| I assume the second private was supposed to be public?
| gumby wrote:
| Yes, thanks. I was still in the edit window so I fixed
| it.
| hinkley wrote:
| I wonder how many different ways people have tried cut and
| cover over the years. I'm talking here of the horizontal part
| of the project, not the vertical. It seems like you usually
| have one, or maybe two, moving work sites, and they go block
| by block removing the street, and replacing it behind them at
| some point. Any business near the sites is choked off from
| foot traffic for a while, even if the site isn't in front of
| their door yet.
|
| Is it more or less disruptive if you do a checkerboard
| pattern instead? Instead of n months of construction around
| your favorite coffee shop, would it be better to have n/2
| months of construction now, and n/2 months of construction in
| July? Maybe that depends on where you are on the street. If,
| for instance, you start at both ends, then the businesses in
| the middle of the cut have construction sites boxing them in
| for almost twice as long as anyone else does. Or maybe that
| just means more people of means mad at elected officials.
| bluGill wrote:
| The problem is the street overall is blocked off for the
| duration. Sure it looks like only one block is stopped, but
| in reality people who have to travel that block are backed
| up all the way, and so they will look for alternate routes
| for the duration.
|
| If you could build the entire thing in 2 weeks (per year)
| people would be happy with a full road closure - they would
| all take vacation for those two weeks. This is for the
| entire city - close all roads to non-emergency traffic for
| two weeks, fix them all up - everyone not involved in road
| work or essential services would just go on vacation. You
| cannot do this of course, but that is what people really
| want.
| hinkley wrote:
| I thought about that too. The problem with trains is that
| they always need to run in the primary direction of
| traffic. So you can't really build them on cross-streets
| and avoid disrupting the main thoroughfares. Otherwise
| you'd often end up with a train to nowhere. The main
| exception being when traffic is curved, going around some
| obstruction that the train can cut across.
|
| I recall when South Lake Union got its trolley, one of
| the things they pointed out was that property values next
| to a trolley drop, but property values 1 block away go up
| more. Everyone wants to be a couple blocks from transit,
| not living above it. So even if you avoided the main road
| going parallel to it, you're probably tearing up even
| more desirable real estate and commercial zoning.
| asdff wrote:
| What people often forget about modern cut and cover is that
| it is only disruptive for a short period of the project
| because they can put a temporary road deck over the cut and
| do most disruptive work overnight. Its how LA metro built a
| subway station in the middle of Beverly Hills.
| bluGill wrote:
| There are several options to make cut and cover less
| disruptive. Other options are dig in the sidewall supports,
| then build the cover over the current road surface, finally
| dig out underneath. It is still tunneling, but it uses most
| of what makes cut and cover cheaper than a TBM.
| kdmccormick wrote:
| Did you read? Article states that cut and cover is still much
| cheaper technically, but can end up being practically more
| expensive due to the political/legal ramifications of the
| surface disruption.
| mc32 wrote:
| Depends, Gaoxiong did a C&C and they were able to mostly
| mitigate the second order effects of C&C. Yes, in some
| sections some traffic was affected more, but apparently it
| wasn't widely disruptive. It can be done.
|
| It helps when you can complete the project in a few years and
| not take a decade to build out a single line. So politics
| does have an impact on feasibility and practicality of C&C.
| masklinn wrote:
| > As far as I understand it, and this may be outdated cut and
| cover is way cheaper than boring.
|
| When you ignore all the side effects, sure (especially if you
| also ignore the risks of blowing the timeline).
|
| Trenchless tech is spreading fast even in small-ish (street
| utility scale) construction.
|
| > Maybe new boring machines are faster and cheaper than they
| used to be.
|
| I'm not sure that's even the case, AFAIK TBMs are still custom-
| built for the job, highly geology-dependent, and require a ton
| of babysitting. If you hit an unexpected patch of really
| different geology things can get really dicey.
| bluGill wrote:
| > TBMs are still custom-built for the job
|
| This is semi-true. They are built for the job, but the design
| is standard. What is custom is the exact size of the tunnel,
| and thus all the supports.
|
| TBMs generally last a lot longer than the job, so a city
| could save a lot of money if they planed to keep using their
| TBM, constantly digging tunnels. Start with a north-south
| line, then use the same TBM to build an east-west line (or
| southeast/northwest), and so on. However most cities are
| unable to find the continuous budget to do that and so when
| they are ready for the next one the old TBM is no longer
| worth using, and in any case they no longer have trained crew
| to run it.
|
| > highly geology-dependent,
|
| Soft water logged earth needs different machines from hard
| rock. There are combination machines, but if you can
| determine which you need you save a lot of money ordering the
| geology specific machine. Get this wrong and you end up with
| a TBM and partial tunnel under the city.
|
| > require a ton of babysitting.
|
| 12 people per shift is the number I've heard (NYC uses double
| which is one of the smaller reasons things cost so much
| there). The work is mostly routine though. However the TBMs
| do break once in a while and they everything stops while you
| repair them.
| matthewmacleod wrote:
| The article discusses this extensively.
| hinkley wrote:
| There's the construction cost, and there's lost income from the
| people who voted for you. Not all of the money spent on
| construction is tax dollars.
|
| Think about every time you've been stuck in traffic because
| there are 3 roads that get you from A to B, and some jackass at
| city hall thought it would be a good idea to permit road work
| on 2 of them on the same day.
|
| We are used to highway on-ramps being replaced in days to
| weeks, but removing an entire street, digging up everything
| under it, being careful not to nick the utility lines and
| pipes, then packing dirt back in around them without tearing
| them, then rebuilding the street on top, that's a lot.
| Especially for the businesses on that road.
|
| We end up with transportation solutions that are suboptimal
| because we don't have the political will to tear off the
| bandaid. This on-ramp is in the wrong place because the old one
| was in the right place, but was built in a terrible way and had
| to be removed for safety while still handling daily commutes.
| epistasis wrote:
| I'm very grateful for those posting and upvoting interesting
| construction articles on HN, this is a key area of our economy
| that is stagnant and could really use some improvement.
| Traditional media do a terrible job of coverage, and spreading
| articles like this helps get better mainstream coverage.
|
| A lot of the bad things about construction come down to incumbent
| players being able to force extremely costly methods on anybody
| who wants to improve the world. So a lot of the challenge is
| political. Solving political problems is really hard, but when
| technology can sidestep the problem, there's a lot that becomes
| possible.
|
| For those in the Bay Area, we are seeing aversion to cut and
| cover be a huge hassle for our stations. The depth of some of the
| new transit stations will be a huge inconvenience for generations
| of transit users, all to satisfy a short term disruption of a far
| smaller number of people. This problem could have been solved
| with money, for those affected, if it were not for the politics.
| theluketaylor wrote:
| Deep stations are also unbelievably expensive. Deep tunnels are
| not that bad, but the resulting stations explode the budget for
| transit to the point getting the project green lit in the first
| place is nearly impossible. Plus with the same set of dollars
| you are building a lot less transit.
| hinkley wrote:
| The deepest station in Seattle has smelled like someone tried
| to make cheese from moldy gym socks since the day it opened.
|
| I believe it opened and immediately shut again so they could
| try to deal with the water problem [though responder says
| no]. I went through when it was briefly open and again after.
| They made it less bad, but it was still pretty awful.
|
| A club I belonged to met at a library near the station so it
| was easiest for me to just hop on the light rail after work
| and then take it back to the bus terminal after but gods did
| I want to hold my breath the entire time.
| oasisbob wrote:
| > The deepest station in Seattle has smelled like someone
| tried to make cheese from moldy gym socks since the day it
| opened.
|
| Maybe it's just a matter of opinion, but I never found the
| Beacon Hill light rail station to smell like anything other
| than raw concrete, similar to DC metro or any other deep
| tunnel system.
|
| I lived in the neighborhood at the time, and don't remember
| the station shutting down due to water ingress. Opening was
| delayed due to issues with overexcavation, but that threat
| was with sinkholes opening to the public above, not issues
| with the tunnel itself.
| hinkley wrote:
| My nose is pretty good at picking up mildew smells. I've
| been in plenty of rooms where half the people can't smell
| anything.
|
| After years of rhinitis my sense of smell is half-shot,
| but I can still walk into a room and find the forgotten
| towel moldering away under a chair or table. Why couldn't
| I have lost _that_ power and kept something more
| pleasant?
| jessriedel wrote:
| Deep stations also add a bunch of hassle for the users. It
| just takes longer to get down 5 stories underground.
| interestica wrote:
| It's absurd to talk about transit times to destinations
| when just getting to track level and back can take longer
| than the trip
| bombcar wrote:
| This is one of those things that people overlook. Travel
| times should be "door to door" or some similar
| comparison; sure it makes cars look a bit better but it
| can make things like trains and walking look even better.
| A two hour flight might be bounded by 1+ hours on either
| end (including security, etc), whereas a two hour train
| ride might literally be two hours + five minutes walk on
| each end.
| bregma wrote:
| You need to factor in the fact that adjoining landowners
| are often rich campaign contributors, whereas the patrons
| of public transit are often the poors or the invisible
| help.
|
| As is often the case, the answer is "follow the money".
| crazygringo wrote:
| Exactly. When I get to a cut and cover station, it's often
| just a single flight of stairs down. It's often only 15
| seconds or so to reach the track and wait for the train.
|
| Stations along bored tunnels sometimes take as much as 5
| minutes to go from street to train. One I used to regularly
| use had three separate multi-story escalators, in addition
| to long walkways between them.
|
| So even if cut and cover disrupts businesses and car
| traffic, I can't help but wonder if decades of extra delays
| to reach the tracks from many thousands of people a day
| doesn't wind up outweighing _that_.
| JoshTriplett wrote:
| Is there a reason bored tunnels need to be
| _substantially_ deeper? Does boring lead to structural
| stability issues that the installation of the tunnel
| structure doesn 't mitigate?
| jessriedel wrote:
| I do know that tunnel boring machines can disturb the
| surface, and that substantial effort goes into minimizing
| this. (That is, minimal surface disturbance isn't
| automatic on account of the fact that you're boring.) I
| believe it sometimes has to do with how much pressure
| they need to apply to the tunnel face; the ideal pressure
| for cutting can lead to sink or swell on the surface.
| Presumably this is less of an issue the deeper you go. I
| don't know much about this stuff though. This is maybe
| relevant:
|
| > This thesis summarizes and evaluates the performance of
| Tunnel Boring Machine (TBM) construction in Singapore's
| MRT network. Surface settlement induced by the tunneling
| process can cause damage to underground utilities and
| foundations and buildings and/or disrupt daily life by
| damaging roads and pavements, and is used in this thesis
| as a measure of performance.
|
| https://dspace.mit.edu/handle/1721.1/82809
| wolverine876 wrote:
| Why are deep stations expensive but tunnels cheap? I'd guess
| the opposite, tunnels being larger.
| jltsiren wrote:
| In an urban subway line, stations may cover ~25% of the
| line. The platforms are long, while the distances between
| stations are often short. And while tunnels are
| standardized and their construction is largely automated,
| each station is a unique project that needs to be adapted
| to the specific location.
| bluGill wrote:
| Because you need to dig out all that dirt, and this is
| normally done cut and cover. Even if you are only digging
| for stairs and elevators (building the station in the
| tunnel as Madrid does) that is a long way down. For shallow
| stations you can tell most people to walk down the stairs,
| but for deep stations nobody will so you have to build
| enough expensive elevators to handle everyone (and you
| still need the stairs for fire escape). Deep stations also
| mean people will be on the elevator longer so you need even
| more of them. (people may be running late so they need to
| load fast and it better not be long for the elevator to
| come when someone needs to get someplace)
| wolverine876 wrote:
| > elevators
|
| How are the elevators any more of a problem than in
| buildings, where they are commonplace, often for much
| taller structures (i.e., many more floors), and not
| considered a major expense?
|
| Edit: Thanks, good points about the volume/throughput.
| throwaway22032 wrote:
| Metro stations have enormous throughput in comparison to
| a building.
| steveBK123 wrote:
| A subway station needs to be able to handle, during rush
| hour, bursts of 100 people arriving every 2-3 minutes. A
| building generally does not.
|
| This is why even deep subway stations usually go with
| multiple levels of escalators to keep the flow of people
| moving continuously.
| kjkjadksj wrote:
| Escalators usually carry more people if they are offered
| at least. Elevators get disgusting fast.
| bluGill wrote:
| For deep stations they don't work as well - you end up
| with a lot of switch backs.
| nradov wrote:
| In the SF Bay Area, BART closed the station restrooms and
| so now homeless people and drunks use the elevators and
| escalators as toilets
|
| https://www.sfgate.com/bayarea/article/Rights-group-sues-
| BAR...
| wasmitnetzen wrote:
| Could be of note that Stockholm is building the world's
| second-deepest subway station right now[1]. Though there's no
| real alternative to that because it needs to go under water
| (well, in the ground under water) towards the next station.
|
| [1]: https://www.youtube.com/watch?v=TEYvywnJy78 (Swedish)
| theluketaylor wrote:
| When there isn't really a choice, fine build a deep
| station. Montreal is building a station 72m down, but it's
| driven by surrounding geography. What's a bad decision is
| deep tunnelling just because, like Toronto on the York
| subway extension. Deep bore under suburbia is really
| wasteful spending and that same transit budget could be
| building a lot more transit.
|
| https://en.wikipedia.org/wiki/Edouard-
| Montpetit_station#REM_...
| pchristensen wrote:
| I lost 25 lbs in 6 months running down and walking up the
| looooong escalators in Stockholm because it took way, way
| too long to stand and ride.
| MichaelZuo wrote:
| How could this problem be 'solved with money, if it were not
| for the politics' ?
|
| Directly paying everyone living/working nearby to get them to
| accept cut and cover construction? Wouldn't that cost even more
| then building it deep underground, after all the legal fees and
| court challenges, once it's said and done?
| theluketaylor wrote:
| It would depend on the implementation. Cut and cover could be
| done in blocks rather than shutting down long corridors at a
| time, combined with legislation setting clear limits on
| affected compensation and their standing to sue over small
| delays. That could easily pencil out to much cheaper than
| deep bored tunnels and stations.
| MichaelZuo wrote:
| Legislation that restricts local resident's standing to
| sue? Can you provide some examples where that has ever been
| implemented in the US, in any scenario, or even judicial
| opinions to that effect?
| steveBK123 wrote:
| NYC is paying $4B/mile for their latest tunneling projects.
| That works out to $200M/block.
|
| Lot of money to go around, I'd argue its more political will
| than cost.
|
| Don't forget theres years of legal fees & court challenges
| even with deep tunneling!
| pchristensen wrote:
| Alon Levy's Transit Construction Costs project breaks down
| where NYC's (extremely) high costs go -
| https://pedestrianobservations.com/2023/02/06/our-
| constructi...
|
| There's no simple reason - basically everything that _can_
| cost more, does.
| immibis wrote:
| This problem couldn't, but a lot of others could. Grandparent
| comment spoke generally about all construction.
| beau_g wrote:
| Here's my startup thesis for this space, free for anyone who
| wants it
|
| 1. Most delays in tunneling projects are due to elongated
| decision making processes 2. The majority of the cost of the
| machines are their initial construction, not operation or
| maintenance
|
| Solution: fleet of TBMS are set off in arbitrary directions
| that bounce off the city borders like the screen saver with the
| bouncing ball. This creates a large network of tunnels all
| across the city. When it comes time to decide to put new
| infrastructure in, one of these tunnels is already there
| somewhere close, just have to dig down to it. 0 decision
| fatigue/cost, max efficiency for cost per tunnel foot.
| yawnxyz wrote:
| If you're ever in Sydney, go to the St. James station (I think)
| and you'll see lots of historical photos of using horse and
| carriage to build the first Sydney metro stations. Very very
| cool!
| hinkley wrote:
| I hear there's a museum in Tokyo as well. When I was there in
| the 90's they were excavating a station that was found by a
| construction crew. The plan was to turn it into a subway
| history museum. I was told that the line was abandoned after an
| earthquake, and they lost track of the location of some of the
| stations (or at least, this one).
|
| It was on a green strip of undeveloped land, so I have a small
| suspicion that a landslide may have been involved. I mean how
| else do you 'lose' a building?
| bobthepanda wrote:
| It is highly doubtful that anyone in bubble-era Japan "lost"
| a piece of property. The rail companies in particular are
| keen, savvy property developers.
|
| During the bubble, the Imperial Palace grounds had a higher
| real estate valuation than all of California.
| hinkley wrote:
| I feel like you might be underestimating the age of subway
| lines.
|
| 2027 will be the centennial anniversary of the Ginza Line,
| and that's a baby compared to Paddington Station, which had
| its sesquicentennial a decade ago.
|
| Apparently the Tokyo postal service had a private line in
| 1915. I kinda wonder if that's the one they 'found'.
| tareqak wrote:
| I think we should find ways to get ahead of the disruption that
| construction creates.
|
| I know people and cities do not at all work in the way that I am
| about to describe, but imagine being able to shift the population
| of a city and all its necessary infrastructure to a second backup
| city so as to minimize disruptions.
|
| All the necessary modifications could be made to the first city
| without affecting people living there because they would be
| living and working elsewhere until the work was complete.
|
| Once the work is complete, everyone would go back to whatever
| address they previously had in the first city, and then work
| could start on improving the now vacant second city.
|
| Obviously, there are lots of issues that I have not described
| like how this works when many places already have a housing
| shortage, and having to build that second city in an "empty" area
| that can be provisioned with the same quantity and quality of
| resources enjoyed by people of the first city.
|
| In addition, I think a large complicating factor in construction
| today is something that I have not seen people talk about: when
| is it a good time to tear down existing structures. The lack of a
| "best before"/"expiration date" means structures stay up until
| failure or until the current owner wants to build something new
| in its place. The building stays up with possible inefficiencies
| (heating, cooling, energy use) that might be too expensive to
| remedy because of the age of structure.
| bobthepanda wrote:
| Concrete alone is 4-8% of global annual emissions, so I would
| imagine once you factor the carbon impact of destroying,
| hauling away the rubble, and then making, transporting new
| building materials, the net impact is not good. There is a
| reason why most cities are targeting retrofits.
| https://en.wikipedia.org/wiki/Environmental_impact_of_concre...
| asdff wrote:
| Its amazing disruption is even relevant to the discussion at
| all. Cities should not be so brittle that having two lanes on a
| single road go down for a cut would make a dent. In reality
| they aren't, but people are emotional beasts, _they_ don 't
| want to have to detour their longstanding commute for reasons
| they don't see themselves benefiting from. So they dig in, and
| decide this couple block stretch of road surface is the hill I
| die on, and local politicians better be damn sure to listen
| because no one else votes in local elections but these
| emotionally driven pissed off people. The whole time the press
| is pandering to them with false equivalency two sides
| reporting, when really the story is often about suburban car
| driving wealthy people being mildly inconvenienced for maybe 20
| months so that the working class can see a generational
| improvement in mobility, and this is somehow an unacceptable
| tradeoff to make because of the status of these people.
| michaelt wrote:
| _> Cities should not be so brittle that having two lanes on a
| single road go down for a cut would make a dent._
|
| Unfortunately, as far as I can tell the way democracies fund
| major construction projects is to first wait until the
| existing infrastructure becomes _completely unbearably
| overloaded_ , and only _then_ to kick off a process that will
| solve the problem in 10 years time.
| bluGill wrote:
| You seem to think road lanes are cheap. They are not. My
| local library has thousands of books not touched on a typical
| day. The only roads not touched on the typical day are in new
| developments not ready for building construction to start,
| once the first building is occupied those roads will also be
| used every day.
| immibis wrote:
| Tell me, if a shelf had to go out for repairs in your local
| library, would it damage everyone who touches the books on
| that shelf, or would they simply be moved to a different
| shelf?
| bluGill wrote:
| If a shelf was millions of dollars you can bet my local
| library wouldn't have any more than they needed. Because
| a shelf is cheap my library can afford to have extra.
|
| Also selves in my library are redundant in ways road
| lanes are not. If you move a book across the library that
| isn't a big deal, but if they move the book to a
| different city that would be a problem. Likewise, even if
| there was an extra road lane someplace, if it isn't close
| and going in the right direction it is not redundant.
| asdff wrote:
| Every given day there's probably dozens of miles of lanes
| that are closed due to crashes or refurbishment. Probably a
| lot more than that depending on where you cast your net.
| Whats another stretch of road going to do on aggregate
| anyhow? When bridge work or sewer work goes on over these
| same roads they go down for years too, sometimes totally
| down with no travel at all, e.g. in LA it took the city 8
| years to replace the 6th street viaduct in Downtown LA and
| traffic was forced to detour for nearly a decade. Yet the
| sky didn't fall, things carried on basically how they
| always have with hardly a noticeable impact, and now that
| the bridge is open today I wouldn't say that traffic in the
| nearby area has been dramatically changed one way or
| another. There was plenty of redundancy and spare capacity
| in the network as it were.
| givemeethekeys wrote:
| Hear me out: tunnels for cyclists. If tunnels are cheap, and I'm
| guessing small tunnels are cheaper than big tunnels, then we
| should have tunnels for cyclists - maybe even right under the
| sidewalks.
| syndicatedjelly wrote:
| This is pretty common in Denver. There are lots of
| pedestrian/bicycle-only tunnels under many main roads just in
| my area. They recently spent a few million dollars improving an
| intersection nearby, and in the process added another cyclist
| tunnel underneath. It makes me really happy to see the city
| prioritize cyclists.
| wolverine876 wrote:
| The tunnels are ways to cross the road - rather than a
| stoplight and crosswalk - or they follow the road and are
| essentially the bike lane?
| drivers99 wrote:
| My guess would be underpasses like along the Cherry Creek
| trail, but I wouldn't call those tunnels. It's also not
| very usable when it floods. Skip to 8:50
| https://www.youtube.com/watch?v=M2z76dDcT8c
| syndicatedjelly wrote:
| Up in Westminster/Broomfield, there are several actual
| bike tunnels that go underneath a main road e.g. on Big
| Dry Creek bike trail underneath Wadsworth Blvd.
|
| The tunnels do get a bit wet/impassable if it has rained
| or snowed heavily, or if the nearby creek is running
| heavily (which is rare). But people dont typically bike
| in downpours.
|
| It doesn't really matter, the point is that cyclists are
| totally separated from car traffic.
| syndicatedjelly wrote:
| Yep, usually underneath a freeway, railroad, or major
| roadway
|
| https://cloudfront.traillink.com/photos/big-dry-creek-
| trail-...
|
| You can bike along Big Dry Creek Trail for about 10-15
| miles without ever having to interact with car traffic. And
| it runs right across a major suburb of Denver. I actually
| use it almost every day to commute for errands
| piva00 wrote:
| Cycling in tunnels would be incredibly depressing if it's long
| stretches of a route.
| givemeethekeys wrote:
| I'll bike in a tunnel all day long before risking it on
| public roads anywhere in America. At least for any kind of
| commute.
| bluGill wrote:
| I'm on my bike to get someplace, not to enjoy the ride. I
| know my route to work. I know the alternates as well where
| they exist. There is no longer anything new to see so I'm not
| looking (except to watch for cars of course)
| piva00 wrote:
| I'm also on my bike almost daily to get someplace, doesn't
| mean I don't enjoy the added benefit of scenery change,
| trees, being able to take a detour if I'm bored out of my
| mind of the same route, etc. Crossing the bridges in
| Stockholm always give me a lot of joy overlooking the
| water, seeing the city.
|
| Being underground for most of my commute would be utterly
| depressing, I enjoy biking to see the world, not to just
| teleport to a place.
| notatoad wrote:
| why though? building good cycling infrastructure at grade just
| isn't that difficult, other than finding the political will to
| make it happen. it doesn't take up a lot of space, it's cheap,
| and when it's at grade it provides easy access for cyclists to
| stop at all the shops or other destinations along their route.
|
| the biggest impediment to cycling infrastructure is a social
| perception that cycling is elitist, and that spending money on
| it is a waste. if we can't even fund an 3m wide strip of
| asphalt or a couple of jersey walls to protect a bike lane, how
| are you going to find the money for tunnels?
| ta1243 wrote:
| At grade is awful, stopping everywhere. That includes in
| Amsterdam.
|
| Benefits of tunnels would be
|
| * No need to stop
|
| * Protection from elements (I for one would be far happier
| riding in summer if it wasn't sweltering, or in winter if it
| wasn't bitterly cold and rain)
|
| * Mostly flat tunnels (No hills to climb up and over)
|
| * Certainty that the route won't be removed for some reason
|
| Of course would never find the money.
| thimkerbell wrote:
| Eyes on the street.
| wolverine876 wrote:
| While I support the infrastructure, I don't entirely agree
| with the analysis:
|
| On city roads, a lane is very valuable real estate. As a
| simple example, taking a lane out of a busy NYC street can
| have a big effect on car traffic.
|
| > the biggest impediment to cycling infrastructure is a
| social perception that cycling is elitist, and that spending
| money on it is a waste.
|
| IME it is elitist, unfortunately. I see mostly delivery
| people and 'elites' cycling in the city, and the cycling
| clubs advocate for a lot of infrastructure but they don't
| make much effort to bring people into cycling. The
| infastructure is highly underutilized - it looks like those
| cycling clubs insisted on building that infrastructure just
| for their small membership.
|
| It's a real risk to the infrastructure: Eventually other
| people are going to notice and say, 'why are we bothering
| with it' and 'let's use the mostly unused space for this
| other project'.
| wbl wrote:
| So valuable we let people park on it for free. As for
| utilization it's far more space efficient: we have a path
| in my town that handles a few thousand people while a
| street that did the same would be unpleasantly busy.
| wolverine876 wrote:
| > So valuable we let people park on it for free.
|
| Most cities have a large infrastructure to manage
| availability of parking, including laws, signs, meters,
| and meter enforcement. And in many of them, parking space
| utilization is very high.
| unregistereddev wrote:
| I'd argue the biggest impediment to good cycling
| infrastructure is the low utilization of the existing cycling
| infrastructure. I had a friend who insisted that most people
| want to cycle to work, but they are lacking the
| infrastructure. If we only build more bike lanes and bike
| paths, more people would choose to cycle instead of drive.
| The thing is, my city has an extensive set of bike paths.
| They're really nice and are a viable way to get places.
| They're also rarely used except for exercise or leisurely
| strolls.
|
| Given most bike paths in my city are empty most of the time,
| why would we spend money on more cycling infrastructure? The
| low utilization - not a social perception - are why spending
| more money would be a waste.
| bluGill wrote:
| Are you sure they are empty most of the time - bikes are
| small and so you may not notice them even though that paths
| are well used.
|
| Are you sure those paths are viable to get places? In my
| city they appear that way if you don't ride them, but then
| you discover they can't get places because there is no
| useful connections. They have have a fence between them and
| stores. Or they only go through residential neighborhoods.
| Where I live they are setup to drive your bike to the trail
| head and go for a long exercise ride.
| bombcar wrote:
| And then we blow wind down the tunnels, one in each direction,
| so they get a speed boost!
| diarrhea wrote:
| Real cyclists know if there's any wind at all, it's never
| tailwind.
| antod wrote:
| Yeah I felt that one. But it actually makes sense. Due to
| the apparent wind (adding the vectors of wind and bike
| velocities together), and drag being proportional to the
| square of velocity, you will seldom feel a tailwind and
| headwinds will be amplified. And this spread widens the
| faster you ride, even turning lighter tailwinds into a
| headwind.
| wolverine876 wrote:
| One great benefit of cycling is exercising in the fresh air,
| seeing the world, and connecting with the people around you.
| jacobgkau wrote:
| > connecting with the people around you.
|
| For the 0.5 seconds you're next to them before you pass them
| or they pass you?
| wolverine876 wrote:
| That is plenty of time to smile, say hello, say excuse me,
| have a face-to-face interaction. You wave at the child
| staring at you, you make appropriate warm sounds toward the
| dog barking with its tail wagging. You all react together
| to the funny sight, to the ambulance, to the sun in your
| eyes.
|
| You also connect by just seeing what people are doing; you
| are out there with them. You have time and visibility to
| see the whole world, 360 deg x 180 deg.
|
| Also you stop, maybe at a light, maybe to look at
| something, and see and talk to people there. You work out a
| traffic issue by talking and smiling, face to face, not by
| honking and banging on your dashboard. You see friends and
| say hello. You see somebody do something nice and say
| 'thank you'.
| debacle wrote:
| I'll do you one better. You could contour the floor of the
| tunnel, texture the walls properly, and add some fans and
| create a quasi-hyperloop for cyclists.
| karaterobot wrote:
| I'm a big fan of turning some existing roads into cyclist and
| local access only roads, and then discouraging extended biking
| on other roads. Tunnels could certainly be part of that. In
| general, I don't think it's ever going to be safe for bikes and
| cars to share the same roadway any more than it would be for
| cars and pedestrians to travel on the same surfaces. For short
| distances, sure, but not on big arterial routes where everybody
| is at war with everyone else all the time.
| cousin_it wrote:
| Hear _me_ out: elevated, enclosed cycleways with transparent
| walls and ceilings.
|
| - Much cheaper to build than underground tunnels.
|
| - Cyclists get a great view of the surroundings.
|
| - Can be horizontal regardless of terrain, so that cycling is
| effortless.
|
| - Can be climate-controlled, so people can bike all year round
| in any weather.
|
| - Don't cause noise problems like trains or cars.
|
| - And of course make cyclists 100% safe from cars.
|
| I just thought of this idea and it's so amazing that I'm not
| sure why it's not everywhere.
| com2kid wrote:
| > Hear me out: elevated, enclosed cycleways with transparent
| walls and ceilings.
|
| Costs a fortune for window washers and graffiti removal.
|
| They would also end up being used by squatters and for
| dumping trash.
|
| Indeed, with how bad the housing crisis is in America, plenty
| of cities are having problems building any sort of public
| structure that has a roof on it...
| cousin_it wrote:
| Yeah, housing is definitely a bigger problem. I was
| thinking about it for some time, it seems the root of the
| problem is that rich homeowners try to prop up the value of
| their homes, by lobbying to stop new housing construction
| nearby. Basically cities want to grow, but existing homes
| act as a brake.
|
| If that theory is true, maybe one possible solution is to
| pay rich folks to get out of the way. The city can offer to
| buy their land, tear down their home, build an apartment
| building in its place, and pay them a cut of all future
| rental income from that building. This way they won't feel
| like selling now is missing out on future increases in land
| value. They can use the income to live comfortably
| somewhere else, and the city becomes free to build up.
| toast0 wrote:
| The problem with segregating transportation is you then have
| different levels of access.
|
| If I bike on the street, I can stop at any location that
| addresses the street, same as any other street user. If I bike
| in the tunnel, there's not likely a ramp up for every business.
|
| It gets worse when you don't have a bike tunnel on every
| street, because then I need to go out of my way to get to
| destinations off the tunnel street. And all the street users
| will yell at me to get back in my tunnel.
| Night_Thastus wrote:
| Fascinating post! I had no idea about this transition from cut-
| and-cover to TBMs. It's always interesting to see how approaches
| change as technology advances and the ratio of cost to benefit
| changes.
| onthecanposting wrote:
| The author paints with too broad a brush. There is significant
| differences in markets that drive these decisions. Cut-and-
| cover is standard in my state, but the land cost, density, and
| regulatory environment allow this. Directional drilling and
| jack-and-bore is very common for small diameter excavation,
| though.
| Affric wrote:
| > the land cost, density, and regulatory environment
|
| Cheap land, low density, lax environmental regulation?
| LegitShady wrote:
| Depending on how dense the urban area the cost of moving
| utilities even before construction is astronomical. If it can be
| done to coincide with cut and cover it can still be financial
| effective.
|
| It is highly disruptive to the entire area so it really depends
| on where the tunnel is being placed. Appropriate traffic and
| pedestrian accommodation plans are essential.
| renewiltord wrote:
| Interestingly, the existence of TBMs has made SF Bay Area transit
| impossible to construct. Because TBMs exist, cut-and-cover is
| impossible since it can be pointed to as an alternative
| mechanism. However, they are hopelessly expensive here and
| consequently nothing gets built. Fascinating outcome.
|
| I think that's a cool outcome in a coordination problem, where
| added technology makes neither technology workable.
|
| This article was wicked sick, by the way. Great use of
| illustrations etc. This is free? Incredible. It's like the old
| web.
| mike_d wrote:
| The tunnel itself (regardless of method) isn't the expensive
| part. Dense urban environments have a ton of stuff underground
| that was never accurately mapped. People don't like a city
| block bursting into flames because you hit a 4" gas line or the
| building they are in collapsing because it has an unmarked
| piling.
|
| Building up is actually a cheaper solution, we just need to get
| the NIMBYs under control. Imagine how nice it would be with 101
| and 280 being double deckers the whole way.
| fritzo wrote:
| Let's not forget 1989 Loma Prieta quake that caused the top
| deck of the bay bridge to collapse.
| https://en.wikipedia.org/wiki/1989_Loma_Prieta_earthquake
| mike_d wrote:
| Which was actually a lot less dramatic than how people seem
| to remember it. A 70 foot section disconnected at one end.
| https://en.m.wikipedia.org/wiki/File:Bay_Bridge_collapse.jp
| g
|
| Freeway construction has changed a lot since the 70s and
| 80s. We now use ductile concrete that can flex without
| breaking, do extensive soil analysis for footings, and add
| seismic isolation systems in high risk areas.
| sbuttgereit wrote:
| Perhaps, but the Nimitz Freeway probably makes a better
| example for what the commenter you were responding to was
| getting at:
|
| "The highest number of deaths, 42, occurred in Oakland
| because of the collapse of the Cypress Street Viaduct on
| the Nimitz Freeway (Interstate 880), where the upper
| level of a double-deck portion of the freeway collapsed,
| crushing the cars on the lower level, and causing crashes
| on the upper level." (https://web.archive.org/web/2009070
| 7140922im_/http://home.pa...)
| gehsty wrote:
| It will be down to policy not actual lack of data on
| infrastructure. Or is the expensive part the mapping? Or
| maybe the insurance?
|
| Older bigger cities have built huge underground
| infrastructure recently. Londons power tunnels & crossrail
| for example.
| gamblor956 wrote:
| _It will be down to policy not actual lack of data on
| infrastructure._
|
| It's absolutely about the lack of data about historical
| infrastructure. LA's Regional Connector line was delayed
| for years, and the budget ballooned by over a billion
| dollars, due to the discovery of thousands of undocumented
| utility lines (still in use) along the route. This
| necessitated dramatic changes to the project timeline and
| scope, since the construction authority had to reroute all
| of those utility lines.
| thebigman433 wrote:
| Even better than expanding 101 and 280 would be to vastly
| improve the public transit down the peninsula. There is no
| reason going from my apartment in SF to San Mateo should take
| over 90 minutes via public transit. There should be constant
| rapid busses through SF to every Caltrain stop in the city.
| Hopefully Caltrains electrification + timing improvements
| make this all more feasible.
|
| The fact that it's one of the most technical areas in the
| world and we're stuck driving between SF and the valley is a
| disgrace
| fragmede wrote:
| For that matter, why Caltrain? it should all be Bart.
| bluGill wrote:
| The name should not matter. There are sometimes good
| reasons to have more than one operator in a metro area
| for various reasons. However there needs to be one
| fare/transfer system across the entire metro with a price
| cap.
|
| You can have various systems of zones or service levels,
| but there needs to be a maximum cost it is not possible
| to exceed to make it easy to budget. People who expect to
| hit that maximum will not hesitate to use transit or send
| their kids on it and thus are more likely to decide they
| don't need the car (even though a car probably costs more
| most people don't account for the costs of a trip)
| bluGill wrote:
| Places in Italy where there is a lot worse stuff underground
| - like priceless archeological artifacts many to tunnel a lot
| cheaper than the US where there isn't such things (in the US
| there wasn't many materials available that would last in the
| natives trash piles - if there was there would be interest)
| renewiltord wrote:
| Fortunately, younger cities like London and Paris don't have
| the problem that ancient metropolises like San Francisco
| have, so they can build subway at a fraction of the cost of
| $4b/mi that SF needs to ensure that it's built right. There's
| a lot of history in California. Pretty unique in that regard.
|
| To be honest, I like 280 without there being something on top
| of it, but if that's what's necessary to get a rail line down
| there I'd gladly accept it. Just the per-mile cost. Well, I'm
| not looking forward to paying more than half of every
| marginal dollar to the government so it can give it to its
| cronies who just happen to be husbands of famous California
| politicians.
| jlhawn wrote:
| Here I was thinking you were talking about elevated rail and
| putting trains back on the lower deck of the bay bridge...
| but no, you're talking about freeway expansion in the core
| Bay Area? Not gonna happen.
| SoftTalker wrote:
| What's wrong with elevated trains?
| gattr wrote:
| They still make a lot of noise.
| bluGill wrote:
| Newer ones make less noise. The old steel structures in
| Chicago make a lot of noise. The sky train in Vancouver isn't
| silent, but it is not loud: they knew noise could be an issue
| and so built to make it not a problem.
| NoNameHaveI wrote:
| I for one, would much rather live in Elwood Blues's room
| than next to ANY interstate.
| steveBK123 wrote:
| They are very loud, they bathe streets/sidewalks/buildings in
| permanent shade, etc.
| JoshTriplett wrote:
| > They are very loud
|
| Loud and sometimes vibration-inducing. But this seems
| potentially feasible to mitigate through sound insulation
| (both on the train and on the buildings; frankly, our
| buildings should have a _lot_ more sound isolation than they
| do).
|
| https://news.ycombinator.com/item?id=39401709 mentions newer
| elevated trains generating less noise, by designing for that
| requirement.
|
| > they bathe streets/sidewalks/buildings in permanent shade
|
| And permanent rain-cover. Seems like it'd often be a feature
| for many, though a bug for others.
| steveBK123 wrote:
| I live next to a bridge in NYC that carries trains, so I
| have experience here.
|
| The set back from the bridge to my building is about 5-10x
| as far from my window as an elevated train line running on
| an avenue would be.
|
| I have new windows, plus a second set of quiet windows
| installed within the windows. Essentially quadruple pane
| windows. It makes them unusable for ventilation. Plus I
| have sound deadening curtains, sound dampeners on walls,
| etc.
|
| Believe me, it is loud. There is no mitigation you can do
| to make it not noticeable. You can only make it tolerable.
| The cost to get it to that level is not insignificant.
| xvedejas wrote:
| In an ideal world, housing wouldn't be built immediately
| on major transit lines, but a (walkable) short distance
| away. Alas, city planners seem dead-set that new
| construction must _only_ happen within a block of major
| roads or train lines. There seems to be a lot of urban
| malpractice that prevents us from making good choices.
| tomjakubowski wrote:
| it seems to me elevated trains are a lot quieter running
| on concrete structures than on steel, as in NYC and
| Chicago.
|
| It's not apples to apples (light rail + heavy), but from
| experience the elevated parts of LA's Expo Line are a lot
| quieter than the Chicago L.
| bluGill wrote:
| There is mitigation that can be done for the noise.
| However it isn't something you can do - the city would
| have to rebuild the tracks to modern standards.
| thimkerbell wrote:
| And there's something to be said for giving residents and
| visitors spectacular views of the city.
| scheme271 wrote:
| The rain cover is really outweighed by shade/lack of
| sunlight. The shade tends to make the street level
| experience more gloomy and a significantly worse experience
| that people tend to avoid.
| fireflash38 wrote:
| Maybe with climate change and more brutal summers that
| calculus will change.
| NoNameHaveI wrote:
| I recall from a PBS special that in the late 1800s, NYC
| suffered a blizzard that shut down even elevated trains for
| days. Hence, the move towards building underground.
| ant6n wrote:
| They also got rid of surface running cars because of the same
| reason.
| Affric wrote:
| Interestingly, for the suburbs here in Melbourne they offered
| two options for grade separation:
|
| 1. Elevated rail
|
| 2. Trenches with no cover
|
| A series of campaigners in areas with higher property values
| wanted the trenches for "privacy" reasons and in the end many
| of them got them but the elevated rail receiving citizens got
| bike paths, basketball courts, car parks, improved walkability,
| generally more public space.
|
| Having experienced the two, the elevated rail is far better.
|
| The totally new line they are building though will be a TBM.
| nox101 wrote:
| > We used to dig up roads to put trains underneath - cheaply.
| Ever-better tunnel boring machines have made the disruption this
| causes unnecessary.
|
| What? Sure, tunneling machines make less disruption but
| unnecessary? You still have to build the stations, entrances, and
| venting systems. All of those breach the surface and the space
| needed to facilitate the construction still causes lots of
| disruption.
|
| But yes, more public transportation please. Lots of it!
| s1artibartfast wrote:
| They didn't say disruption free. The quantity of disruption
| reduced is the part which is no longer necessary.
| thimkerbell wrote:
| Dang and others, would it make sense to change the HN posting
| workflow such that a one-paragraph ChatGPT-produced summary was
| the first visible comment? Or otherwise make a summary easy to
| find. Also, ask the poster if the title could be improved, and
| suggest a possibly better one? Maybe it'd be unwise, of course.
| 93po wrote:
| The decision makers over HN as a software platform are pretty
| resistant to any sort of change, which is likely a mixture of
| deliberate intention but also lack of incentive to mess with
| what's already working.
| s1artibartfast wrote:
| I think automated summaries encourage shallow engagement and
| poor(er) comment quality.
|
| A summary is not the article, and the map is not the territory.
|
| What do you think they would add, and why do you think that is
| a good thing?
| bluGill wrote:
| What I want is something that says does the article actually
| say anything interesting beyond the headline. all too often
| I've clicked on a link and discovered the headline said it all
| - good for the headline, but bad for in-depth understanding -
| often the commenters know far more than the article.
|
| In this case the article is worth reading. However it also is
| ignoring some important factors and so we still need to read
| the comments.
| kfarr wrote:
| It's not that simple as "TBM is better" as others also have
| chimed in to say here.
|
| Real life example underway now: there's an SFPUC project in SF
| Mission district to improve stormwater drainage. City proposes
| TBM but this will result in _years_ of having a huge tunnel
| entrance work facility in a residential neighborhood. Cut and
| cover would affect specific blocks but only for months and then
| move on to the next. Which is better?
|
| PS. To all the OpenAI folks, this project is happening around all
| your offices!
| Affric wrote:
| To me this sounds like TBM to would still be better.
|
| You're pissing off one set of residents immensely rather than
| every resident in the area sequentially. The marginal harm you
| do to yourself by pissing off residents is diminishing. Better
| to piss off fewer voters.
| arcticbull wrote:
| > You're pissing off one set of residents immensely rather
| than every resident in the area sequentially. The marginal
| harm you do to yourself by pissing off residents is
| diminishing. Better to piss off fewer voters.
|
| This is the kind of thinking that leaves us mired in the
| past, unfortunately. As soon as these projects are completed
| everyone loves them and completely forgets about any minor
| transient misery a couple of restaurants were caused.
| Compensate them and move on. The billions of dollars saved
| using cut & cover vs. a TBM sets up a heck of a compensation
| fund.
|
| There's this real unstated mindset now where nobody should
| ever be inconvenienced, ever, no matter how mildly. It really
| holds back urban development. People will get over it.
| msie wrote:
| I have developed this feeling that the govt is so stingy
| with small amounts to compensate businesses yet are willing
| to waste great amounts in other cases. I guess that's
| politics for you.
| bluGill wrote:
| Robert Moses ran rough over New York for a decade or so and
| they are still paying the price for his roads. We have gone
| too far for sure, but there is a reason we did.
| brailsafe wrote:
| Another real life example of TBM happening now is the SkyTrain
| extension in Vancouver, Canada. It covers quite a distance and
| is rather impressive, all stations being built concurrently,
| with some main road sections needing to be suspended. No
| shortage of complaints, but there were also no shortage of
| complaints when they built a previous line with cut and cover.
| I don't think it would be remotely feasible otherwise.
| jlhawn wrote:
| Recently in the SF Bay Area, there's been a lot of displeasure by
| transit activists that object to VTA's BART to San Jose extension
| (it's being built by VTA not BART) who had the choice between two
| tunneling options:
|
| 1. Two small-bore TBMs ~2 stories underground, one for rail in
| each direction. This would require cut and cover for the
| _stations only_
|
| 2. One large-bore TBM ~7 stories underground, with technically
| enough space to fit an entire station platform inside but
| displaces a HUGE amount of soil/rock along the entire line, and
| require very deep stations that take a long time for riders to
| enter/exit.
|
| VTA consultants went with option 2 because they didn't want to
| disrupt the surface (again, only for the few blocks where the
| stations would be built) even though it costs $$ billions more.
|
| Many transit activists (including me) are upset because it makes
| the project both take much longer and cost more. We could save
| money by literally just giving billions of dollars to the
| businesses on the affected blocks. There's no geo-technical
| reason to go with the large-bore option. This has also led to a
| lot of recent VTA-negativity among these activists.
| Cerium wrote:
| I have the same reaction. It seems to me that we could pay
| every business impacted by the work and come out ahead
| financially AND ahead on quality of service.
___________________________________________________________________
(page generated 2024-02-16 23:01 UTC)