Monday’s Friday Reads – 20 May 2019

On By In Friday Reads

• Hammersmith Bridge closes to cars & traffic evaporates (TwitterThread)

• Birmingham Snow Hill Tunnel sidings (RailBusinessDaily)

• Finland constructing its first intercity tram line (RailTech)

• New Belgrade Centre station as city building (NYTimes)

• LA once again proves induced demand (StreetsBlog)

• Philly 30th Street Station looks to avoid Hudson Yards fiasco (Philly)

• The history of women on wheels (Curbed)

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44 comments

  1. Hopefully in a few years workers will be back in the Snow Hill tunnels, electrifying the lines.

    Not sure it’s true to say traffic evaporates when a bridge is closed, as surely it just goes elsewhere? Especially as this time even buses are barred from using the bridge (Diamond Geezer has an article on this today)

  2. Re Mikey C,

    Agreed the Hammersmith Bridge traffic hasn’t evaporated it has just moved elsewhere with many road journeys extended by upto 30 minutes at the worst times according to local friends.

  3. @Mikey C

    “Not sure it’s true to say traffic evaporates when a bridge is closed, as surely it just goes elsewhere?”

    Surely that’s the point – faced with a more difficult journey, some people simply don’t travel at all. The closure has resulted in some people walking across the bridge to pick up a bus the other side, so there are certainly fewer people travelling by bus across the Thames.

    The number of buses actually crossing the Thames has also reduced, as of the five routes previously crossing the river at Hammersmith, only one still does so: the 209, diverted via Putney Bridge. A half-hourly service on the new 533 via Chiswick Bridge is considerably less traffic than the combined frequencies of the curtailed 33, 72, 419 and 485.

    The combined frequencies of the five routes is actually between thirty and forty each way (60 -80 in total) – LBHF council’s website claim that TfL were sending 100 buses per hour across the bridge is a slight exaggeration. Nevertheless, the frequencies are relatively high for Zone 2 because the weight limit on the bridge (7.5 tons, and only one bus at a time) effectively prohibited larger buses.

    Published service frequencies: 33 6-9 minutes (7-10bph); 72 6-10 minutes (6-10 bph), 209 4-6 minutes (10-15 bph), 419 4bph, 485 2 bph.

  4. @timbeau and others – the traffic does indeed “evaporate”. SACTRA discovered as much back in the ’90s, and the GLC study of the last time that Hammersmith Bridge was closed also found as much. I have not retained a copy of the regression analyses that were done at the time, so I can’t tell you whether road capacity is the first or indeed the third order factor in determining volumes, but on the analogy of some work I commissioned on rail capacity back in NSE days, capacity there was the second order factor in determining volume of use.

  5. Just wondering if and when the penny will drop that maintaining access for all private vehicles many of which are pushing 1.5 tonnes and 4 metres carrying one or two passengers is not feasible or cost-effective in a dense and old city?

  6. The piece on female cyclists ties in nicely with the “Mind the Gender Gap” article, I think .. but one sentence, near the end, caught my attention:
    The report also called for “changing the narrative” of who gets to bike by changing the image of a cyclist from a young, fit, white man to include a wider range of genders, ages, races, and abilities.


    [Duplicate link and off topic content snipped. LBM]

  7. This report from 2002 provides some figures for the 1997 closure of Hammersmith Bridge and about 10,000 vehicles a day did indeed evaporate from the local area.

    http://www.onestreet.org/images/stories/Disappearing_traffic.pdf

    It is clear that some alternative routes will experience an increase in traffic but overall, traffic decreases.

    Back in the late 1990s there were on average about 30,000 vehicles a day and this had declined to about 20,000 before the current closure.

  8. I agree with the idea. On the South Circular in Putney, traffic has never returned to previous levels after it was shut between Wandsworth and Putney for a few weeks a couple of years ago.

    Separately I must say all London Reconnections readers should read about the total failure by TfL to communicate what it is doing with buses because of Hammersmith Bridge coupled with a failure to understand what people south of the bridge actually want. Please read this including the comments…

    http://diamondgeezer.blogspot.com/2019/05/route-533.html

  9. Mogridge demonstrated the point very clearly about 20 years ago. In a saturated road network, like most of London, capacity is the main determinant of volume. As traffic levels increase, average speeds come down until you hit a balance point where the numbers of people choosing to travel to other places, by other modes, at different times or just not at all is broadly equal to the number of new road users. Mogridge showed that in London average door-to-door journey speeds where the main mode is car are equal to those speeds where the main mode is rail. Every attempt to lift traffic speeds encouraged more new users until average speeds regressed to the balance point. Conversely, every attempt to lift rail based speeds (whether by new lines or new or more frequent services) did not have the same outcome and average speeds stayed higher. This made the balance point of the road/rail switch at a higher speed thus lifting traffic speeds. The same holds true even in big cities with poor rail services, such as Istanbul or Sao Paulo. Only here the balance point is walking speed and traffic is perpetually very congested.

  10. There is a major difference between now and 1997 though in that it’s all traffic which is banned, whereas before buses (and motorbikes) were allowed to cross the bridge. In 1997 anyone needing to go to Hammersmith from Barnes would take a bus instead, indeed with the cars removed the buses became much more attractive to use.

    Now the buses are affected as well, so the public transport alternative to driving across the bridge is less attractive. As we are in spring and approaching summer, walking or cycling over the bridge is quite a nice option, will the same be true in November?

    And a significant amount of road traffic nowadays isn’t people getting in their private cars and driving somewhere, but rather comes from Ubers, online supermarket shopping, online Amazon/ebay shopping, takeaway mopeds etc, I can’t see people changing their habits because a bridge is shut, the drivers will just reach them using a different route instead.

  11. The Belgrade station video may be hosted by the New York Times, but it is an advertisement feature – the closure of the historic station in Belgrade in favour of a suburban new build is hugely controversial, and likely to be detrimental to the rail network in the region.

    This paid-for feature glossing over the fact that Serbian rail traffic has been pushed out of town to an unfinished and inconvenient concrete bunker is pure propaganda, probably funded by the developers who wanted the old station site.

  12. @Paul – funded by developers

    The Guardian did a feature some three years ago about the Abu Dhabi funds behind it.

  13. One hates to be excessively pedantic, but Hammersmith Bridge is not closed to traffic – it is only closed to motor vehicles, which are a sub-set of traffic.

    Cycling in November tends to be fine, by the way. There are slightly more rainy days on average than usual (10) but while cycling in the rain requires preparation and equipment it’s still usually a better experience than being packed onto a bus or train with lots of damp commuters, or having to wait in queues of cars.

  14. @PAUL, @ALEKS – The new ‘Central’ station gets a very mediocre user rating on Google.
    https://goo.gl/maps/p49eDMT3mh9wq4Qc9
    It appears just too far out from the centre to be easily walkable, the wrong side of a big inner city highway and has very poor bus links. The old station was clustered together with a central bus terminal and was at the centre of the tram and bus network. The new one seems deliberately placed to be as disconnected as possible from the city it is supposed to serve, and cannot be very good for promoting any kind of rail traffic into the centre, especially commuter flows. The very antithesis of integrated transport planning.

  15. “Cycling in November tends to be fine”, for fit younger men, perhaps. I know some people would prefer to stay in warm dry cars and wait in traffic even if it takes longer.

  16. With a little bit of imagination, and with the passengers’ interests at heart rather than the operators’, TfL could run buses to each end of the bridge allowing people to walk across with a ‘golf buggy’ for those unable to walk.

  17. @RogerB – according to TLB, TfL are having difficulty in finding places to turn the buses at either side, none of the available side streets being very near to the bridgeheads..

  18. Is the bridge so weak that it could not cope with a very small bus? Something specifically targeted just for those who aren’t able to walk over the bridge. A vehicle like the Mercedes Sprinter bus (the sort of vehicle the car rental companies at Heathrow use to shuttle passengers to their pounds on the Bath Road) is about 5 to 6 tonnes. I suspect tfl have a few similar vehicles on their fleet for dial a ride services.
    The diamond Geezer account is very depressing – tfl communications about bus diversions are always utterly hopeless.

  19. @GrahamH – There are side streets, but it would need a three point turn to change direction and I suppose buses aren’t allowed to reverse on a public highway; so it would need a couple of banksmen as well as the shuttle driver…..

  20. @John I see plenty of women, old people, and cargo bikers cycling in the winter. They tend to be quite hardy.

    If your average power output is low it’s actually easier to dress for the contions, because you don’t have the same highs and lows to contend with as if you can push an 800w peak.

    The difference is akin to:

    – drinking a cup of tea while wrapped in a blanket,

    or,

    – trying to regulate your temperature while sitting in a freezer armed with a microwave that can run for 10 seconds every 4 minutes.

  21. There is no blanket ban against buses reversing on a public highway – that is a myth – it happens quite a lot in rural areas. However, you are probably correct that such a manoevre would not be consdered safe in this case, given the nature of the streets and the area, and the frequency of the routes in question.

  22. @ Island dweller.

    The bridge is banned for all motor vehicles, because it is danger of collapse. 6 tons is close to the existing limit anyway, and a wheelchair lift fitted model would be at the high end of that weight range.

    And I suspect if minibus shuttle service were provided, the sharp-elbowed would crowd out those who really needed it.

  23. RogerB
    With a little bit of imagination, and with the passengers’ interests at heart Yes, well, that’s the problem, isn’t it?

    Timbeau
    How about, say 5-10 repurposed electric milk-floats, fitted with basic chairs ( Max load 10 persons? ) circle-shuttling across the bridge?

  24. @GT: As long as Ernie’s not driving….

  25. Even accepting that Greg probably had tongue in cheek…. Those old milk floats used lead acid batteries – not the (slightly) lighter lithium batteries that new electric vehicles use. Typical gross weight of those of milk floats was five and a half tonnes, so that rules that out.
    If the bridge is so weak that it can’t take a six tonne bus, how can they be sure it’s safe for pedestrians and cyclists. If you get a rush hour crush of people for some reason, couldn’t that be the same load as a bus? (Declaration – not an engineer – genuinely puzzled how they make these decisions)

  26. I recall Hammersmith Bridge being closed in the late 70s and bus services terminating each side for pax to walk between without issues about reversing being an issue*. The real problem though is the very length of the detour, as the alternatives of Putney and Chiswick bridges add around four miles to a journey.

    (* iirc at one point we all had to get off the bus – routemasters – and walk across whilst the bus went over empty and waited for us)

  27. It depends on whether its the deck or the cables which is the problem. If it’s the cables, yes, it’s the total weight which is relevant. If it’s the deck what matters is the weight on a given point

    A bus distributes its weight on just four points of contact. The equivalent weight of people is distributed over more than a hundred points of contact.

  28. @Alison W

    Even an empty Routemaster weighs 7.5 tons.

    A full one weighed about 12.5 tons (the same as an empty Borismaster – such is progress)

  29. @timbeau
    So if they put the body of the bus on caterpillar tracks, or suchlike, it might be OK?

  30. @timbeau – I guess it also depends on whether the pedestrians avoid (accidentally) keeping too much in step, although the risk of a marching army must be slight…

  31. @Graham H

    That was the problem with the “wobbly” Millennium Bridge, as it started to sway, people adjusted their gait to the sway, thus reinforcing the swing.

  32. Zipwires hung from the towers?
    Free roller-skates?
    A fleet of pedicabs? ( Thus actually making the things useful for the first time? )
    A fleet of those battery-electic scooters?
    Any more ingenious “solutions” to the problem?

    [Mod’s note: Would commentors please refrain from rising to this challenge. Some humour is OK, but we are getting somewhat carried away… Malcolm]

    And, Timbeau …
    If you look at Diamond Geezer’s photograph(s) it appears that it’s the decking that is the problem … it looks decidedly dodgy.
    For reference:
    Original article
    And
    Picture

  35. Hammersmith Bridge. Tom Edwards of the BBC has a photo on his twitter stream of a ‘cracked pedestal’. Apparently these are why the bridge is now unsafe for vehicle traffic.
    Not being an engineer I haven’t a clue what that is – but perhaps someone here can interpret

  37. That cracking sounds fairly fundamental to the structure of the bridge, not someone that be easily patched up I imagine

  39. I’m not sure which bits are the pedestals in which the cracks have appeared, but the term suggests an upright, such as part of the towers (which support the suspension cables) or the piers (the bit below the road deck). Both seem to be fairly important structural components.

  42. Cast Iron in Tension.
    Not a good idea – ask Thomas Bouch about that one …..

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