CityCyclingEdinburgh Forum » Infrastructure

No room for segregation...

(31 posts)
  • Started 9 years ago by newtoit
  • Latest reply from Fountainbridge

12

  1. newtoit
    Member

    An interesting question around there being "no space", and apologies if this or has been done to death on an old thread that I couldn't find...

    I was having an argument with the other half the other day about having proper infra on arterial routes. She had the classic attitude that you couldn't possibly reduce road capacity on some arterial routes or there would be gridlock. I did point out that these arterial routes are where people want to go between homes and work, so we should be facilitating cycling as far as possible on these.

    So my question for Edinburgh would be - of the main arterial routes into the city centre, are there any that really wouldn't make sense or be viable for provision of segregated infra?

    For key arteries I'm thinking Queensferry Road, Glasgow Road, Slateford Road (A70), Morningside Road, Newington Road & a route from Cameron Toll to edge of city, Niddrie/Craigmillar Rd, London Rd, Leith Walk.

    Case in point - our "discussion" was on Newington Road. The better half claimed that you couldn't possibly have segregation on that road because 2 lanes are needed each way and without it there would be mayhem... Even ignoring the fact there are 3 parallel streets, personally I'd have thought this would be much easier than the likes of Morningside which is actually quite narrow and congested.

    Of course this also omits the fact that we already have the world class facility in the QBC...

    Assuming the money was available, which routes do we think would be viable or not, and in a realistic but ideal world what would we want to see?

    Posted 9 years ago #

  2. Stickman
    Member

    On the A8 corridor - the stretch of St John's Road between Clermiston Road and Manse Road would be tight. The rest of the route would be feasible from Roseburn all the way to Maybury.

    Posted 9 years ago #

  3. I were right about that saddle
    Member

    @newtoit

    I can't see any reason why Mayfield Road/Causewayside shouldn't be closed to motorised traffic altogether (apart from orthogonal crossings).

    Nobody respects the QBC at all. There was a van parked simultaneously on the double yellows and the cycle lane yesterday at 17h00.

    Alright, the petrol station would kick up a fuss, but the Bike Station would be in clover....

    Posted 9 years ago #

  4. SRD
    Moderator

    Lanark Rd, Calder Rd; some parts of the former probaby have too many driveways.

    slateford rd is ripe for the plucking

    Posted 9 years ago #

  5. wingpig
    Member

    Newington Road is exceptionally straight and of consistent width compared to the others. Seeing as it connects to the loading/parking/junction-fest of South Clerk Street and northwards or the single-lane-each-direction-after-parking Grange Road and is sort of buffered at its connections to Liberton/Peffermill/Dalkeith Roads by Cameron Toll and Lady Road (with load shared by the parallel routes) it could easily support a segregated bike lane at either side if the motor traffic was constrained to 20mph to stop it bunching.
    When I regularly foodshopped at Cameron Toll I tended to take Dalkeith Road back home as it felt less like a potential motorway, though it widened-out and went multi-lane just at the top of most of the climb. The greater population density implied by tenements (compared to the airier houses on Newington Road) ought to mean a decent segregated facility on Dalkeith Road would be a useful thing, but there'd be lots of loading and parking to displace, though making it all one-way for motor traffic would be a way round that (with Newington Road available as the other-direction equivalent, though links between the two get a little narrow and squishy in places).
    Morningside Road is quite similar to Leith Walk - variable in width, lots of shops and tenements, a few junctions where filters are squeezed in and crucially only really busy for half an hour at each end of the working day.

    Posted 9 years ago #

  6. Stickman
    Member

    Queesnferry Road: wide all the way from town to Cramond Brig. Possibly a bit narrower at Blackhall.

    Posted 9 years ago #

  7. sallyhinch
    Member

    I linked to a piece in the last Cycling Embassy blog roundup where a US traffic engineer explained why going from a four-lane road (two in each direction) to a three-lane road (one in each direction, with alternate left-turn lanes (right-turn lanes in the UK) up to each junction) basically has almost no impact on traffic throughput at all, plus you get a road that's much safer for everyone

    Of course, that's a US grid system and the UK is complicated because where we have two lanes in one direction, we do usually make one of them a bus lane so there *would* be an impact on bus passengers unless it's the sort of bus lane that always has a taxi parked in it.

    Edit: link is here http://streets.mn/2016/04/11/the-traffic-engineering-case-for-three-lanes-on-3rd-avenue/

    Posted 9 years ago #

  8. neddie
    Member

    Road capacity in a city is limited by the time it takes cars to move away from stationary at junctions. So if you want traffic to flow "freely", you need to have as many lanes as possible on approach to a junction. The number of lanes further back in the lead up to the junction doesn't really matter (more lanes only facilitates overtaking, which changes the queue order at the junction, but doesn't improve flow).

    You could have 1 lane on the main road, then widening to 3 lanes at the lights and this would work fabulously. Then you can put your cycle lane along the 'other' lane of the main road (often parking or a bus lane in Edinburgh) and make it somehow disappear at the junctions (which strangely(!?) seems to be exactly what happens).

    Of course, all this ignores the fact that traffic is self-limited by capacity - more cars will be attracted to a particular road until that road gets to capacity and starts to become slow.

    By optimising for traffic (cars), more lanes at junctions etc., you will encourage more traffic. If you don't optimise for traffic and make it slower, inconvenient, the opposite occurs - you discourage traffic. It isn't the the case that this displaced 'traffic' will have to somehow 'find somewhere else to go', what actually happens is that people modify their behaviour e.g. don't try to make the same journeys, shorten their commutes, choose another mode, etc.

    Design for bikes, walking and buses and people will use those modes. Design for cars and you'll have a polluted, ugly, gridlocked city full of cars. You decide...

    Posted 9 years ago #

  9. dougal
    Member

    @edd1e_h What happens to the cars after the junction, presumably the merging lanes require traffic to stop, so you've just extended the "junction pause"?

    Posted 9 years ago #

  10. wingpig
    Member

    Queen Street would be a good place to test a three-lane split-off-turning system. If there was a constant/predictable arrangement at each junction it could cut down the stoppages/bunching caused by a vehicle being caught diagonally across two lanes.

    If traffic is moving more slowly it can cope with fewer multi-lane pre-junction reservoirs. Grange Road during term-time would be a good place to test that.

    Posted 9 years ago #

  11. Morningsider
    Member

    A segregated route down Morningside Road would be tricky to fit in, but only on a fairly short section. Certainly, the roads are wide enough to accommodate a segregated route between Lothian Road and as far south as Waitrose. The road widens out again by the Post Office. Would require the loss of a few off-peak parking spaces and floating bus stops.

    A start might be a segregated route between Holy Corner and the Meadows, through Bruntsfield. I would also like to see a cycle only phase of the traffic lights down by Morningside Station, or combined bike/pedestrian phase. This would allow for safe turning on an otherwise scary junction.

    Posted 9 years ago #

  12. neddie
    Member

    @dougal

    I was thinking more a lane for left, one for straight on, one for right turns.

    If you were to have 2 straight-on lanes, then yeah, you would 'need' to have a short section of 2 lanes on the other side to allow zipper-style merging.

    Posted 9 years ago #

  13. dougal
    Member

    Okay I totally misinterpreted your description!

    Posted 9 years ago #

  14. neddie
    Member

    This is a great quote from Andrew Gilligan:

    "Some people think traffic is like rainwater and the roads are the drains for it. If you narrow the pipe, they say, it will flood. If you block one road, they say, the same amount of traffic will simply spill over to the nearest easiest routes.

    "That’s the sort of argument made against our cycle superhighways, or our current proposal to cut rat-running through Regent’s Park by closing some of its gates.

    "But in real life, once the builders have finished, the spill never actually happens. The pipe doesn’t flood; some of the water goes away instead. Because traffic isn’t a force of nature. It’s a product of human choices. If you make it easier and nicer for people not to drive, more people will choose not to drive."

    - See more at: http://road.cc/content/news/187544-anti-cycling-campaigner-claims-bike-lanes-cause-pollution#sthash.Z6gz91sa.dpuf

    Posted 9 years ago #

  15. Fountainbridge
    Member

    Is there any UK recognised widths for a (30mph) vehicle lane, cycle lane and a pavement?

    Can anybody tell me how useful the bus routes are during the rush hour? During the non-rush hour most seem pointless (for buses).

    Posted 9 years ago #

  16. PS
    Member

    @Fountainbridge I believe so. If you reduce the speed limit to 20mph, the roads don't need to be so wide.

    The Edinburgh Street Design Guidance highlights this as one of the changes that will be adopted:
    "
    Road Geometry
    • Using narrower vehicle lanes, consistent with promoting slower traffic speeds which give more space to pedestrians and cyclists, whilst keeping enough width for buses to operate efficiently where appropriate.
    "

    Posted 9 years ago #

  17. Charlethepar
    Member

    The thing that I observe with driver behaviour, is that if there is more than one lane, or even enough room for two vehicles, then someone will be "parked"/ dropping-off/ on the phone/ waiting for their passenger in one of the lanes. The only way to keep traffic flowing is to narrow things to one lane and separate that lane from the lane in the other direction. You also need to protect the pavements with bollards. Drivers seem to finally realise that stopping for their own convenience over others and the law is impractical when they block the whole road.

    Then you would have the same one lane of moving traffic that you started with, without the enforcement problem, or the messy cutting in and out of traffic. You have also freed up lots of space for pedestrians/ bike lanes/ cafes/ petanque courts/ bike racks/ ponds/ art/ etc.

    Posted 9 years ago #

  18. neddie
    Member

    Charlethepar

    Why not go a step further and have a concrete wall to protect the pavements, and another concrete wall to protect the lane in the other direction? You could then cover the whole thing over with a roof to keep the fumes and the noise in...

    Oh wait...

    Posted 9 years ago #

  19. i
    Member

    I think the concept we're talking about has a good name; "Traffic Evaporation"
    http://www.onestreet.org/resources-for-increasing-bicycling/115-traffic-evaporation.

    Traffic evaporation you could say is the opposite of Induced Demand for cars. I suppose there will be the initial disruption as people have to ajust to a different street, but in the long run cycle paths do give greater capacity for the space given.

    QBC could be made one way in sections for cars. I remember someone blogging about that idea.

    Posted 9 years ago #

  20. Big_Smoke
    Member

    The only person who thinks there's no room for separate lanes is someone who couldn't be bothered. Even small areas of NL have found ways to simply reroute traffic to accomplish this.

    Posted 9 years ago #

  21. Klaxon
    Member

    I do believe we're seeing 'traffic evaporation' on Leith St

    The queues into Picardy Pl are nothing compared to what they were when the roadworks started six months ago

    Posted 9 years ago #

  22. gibbo
    Member

    @newtoit

    "the fact there are 3 parallel streets"

    IMO, you've hit on the key here: you could simply make 2 of the 3 streets one way only for vehicles and use the other half of the road for a 2-way segregated bike lane.

    Job done.

    To me, that's the easiest way forward for Edinburgh to have segregated bike lanes: turn a lot of streets into one way for cars, 2 way for bikes.

    Posted 9 years ago #

  23. chdot
    Admin

    "turn a lot of streets into one way for cars, 2 way for bikes"

    There are not too many opportunities for that, but QBiC is one.

    Problem in Edinburgh is always "bus route".

    Posted 9 years ago #

  24. neddie
    Member

    you could simply make 2 of the 3 streets one way only for vehicles and use the other half of the road for a 2-way segregated bike lane

    To me that still sounds like trying to cater as much as possible for the movement of private motor cars, whilst fitting cycling in 'around the edges'. (Don't forget about the countless junctions, 'optimised for traffic flow', that the segregated lanes will have to cross / subserve to).

    Why not instead close North Bridge, Waverley Bridge and the Mound to private motor cars and watch the traffic 'evaporate'?

    Posted 9 years ago #

  25. gibbo
    Member

    @edd1e_h

    "To me that still sounds like trying to cater as much as possible for the movement of private motor cars"

    I'm thinking that people have to get to their homes by car.

    And, if that's to happen, I can't think of a way to ban cars from a street 100%.

    What it will do - aside from creating the segregated bike lanes - is make drivers drive the long way round so they enter the street from the correct direction. Which would be a mild inconvenience.

    Posted 9 years ago #

  26. gibbo
    Member

    @chdot

    "There are not too many opportunities for that, but QBiC is one."

    There are some routes where I can't figure out how to do it - e.g. Colinton Rd.

    But there are plenty of others where it can be done by using side streets. And, even if the cost to cyclists is 10% longer journeys, I'd say it would be a good thing.

    Posted 9 years ago #

  27. PS
    Member

    I do believe we're seeing 'traffic evaporation' on Leith St

    The queues into Picardy Pl are nothing compared to what they were when the roadworks started six months ago

    They may have re-condensed on the Queen's Drive and into Holyrood Road - there has been a noticeable increase in cars coming from the east and turning up Holyrood Gait on evenings when I've been cycling round Arthur's Seat.

    Posted 9 years ago #

  28. Chug
    Member

    Colinton Road
    seems to have no issue with parking along most of its length - mostly just outside the controlled zone where folk leave their cars for the day and jump on the bus. There's a fair amount of space to be gained there....and that's only the two lane section, not the four lane bit up the hill past the Uni.

    Posted 9 years ago #

  29. Klaxon
    Member

    They may have re-condensed on the Queen's Drive and into Holyrood Road

    I've been doing some doodling on the old town on how to remove through traffic from the park and from the Royal Mile.

    I'm pretty happy this map doesn't block the 35 bus and doesn't make any area inaccessible to general vehicles (deliveries etc). It'll put pressure on Holyrood Rd but it's already a bit of a non-place in itself and needs improvements to reduce width and speed ANYWAY.

    What do you think? https://i.imgur.com/mqJJthx.jpg

    Posted 9 years ago #

  30. PS
    Member

    @Chug If there's room for pedestrian refuge island in the middle of a 30mph road then chances are there would be room for segregated cyclelanes when you make it 20mph (with single stage pedestrian crossings).

    Posted 9 years ago #

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