CityCyclingEdinburgh Forum » Infrastructure

20mph road width

(18 posts)

  1. gkgk
    Member

    This might be a bit out of the blue, but today I was walking along the wide (top) bit of W Savile Terrace and it struck me, the road is too wide.

    To make cars do 20mph, without police enforcement, they need to have only two feet tops to spare on either side as they drive, not 4 metres.

    They should narrow the middle bit, move the car parking in, make the old car parking bits into cycle lanes and the central, driving bit of road would be a bit tighter, more 20mph-encouraging.

    Same with the steep hill up from W Savile Terrace / the avenue shop area up to KB. Is that a 20?

    They'd only want to narrow the ones where they can make a full-lane (2m each way min) bike lane out of the spare bit, obviously, to avoid the bikes becoming rolling road blocks.

    Posted 11 years ago #

  2. stiltskin
    Member

    Or perhaps we could conclude that this particular road is way too wide to need a 20mph limit?

    Posted 11 years ago #

  3. crowriver
    Member

    They'd only want to narrow the ones where they can make a full-lane (2m each way min) bike lane out of the spare bit, obviously, to avoid the bikes becoming rolling road blocks.

    Yeah, because that's what they've done on MacDonald Road, Princes Street, Leith Walk, etc. Not.

    Posted 11 years ago #

  4. bdellar
    Member

    Totally. You can see how width affects speed on London Road. Most of it's normal city width, and cars do 30ish. But outside Meadowbank it's extra wide and cars do at least 40. Because they can, relatively safely and easily.

    Posted 11 years ago #

  5. cc
    Member

    I think there's no doubt that 20mph limits need to be followed up with road redesigns which make the road look at a glance like the sort of place where you'd go at a maximum of 20mph.

    Whether that boils down to narrowing the road I don't know. I think there are a number of things you could do. For instance I'd like to see a lot of roads closed off at one end to cars, but through routes for bikes. The CROW manual would be full of good ideas.

    Posted 11 years ago #

  6. gkgk
    Member

    "this particular road is way too wide
    to need a 20mph limit    "

    I agree, Stiltskin. If 20mph is the desirable speed limit for letting pedestrians feel safe and all the other reasons, the driving bit of the road should be set wide enough for traffic at that speed, not wide enough to allow traffic at 50mph.

    Good link, the Crow manual, CC, thanks.

    Posted 11 years ago #

  7. shuggiet
    Member

    Cycled along W.Savile Terrace this evening.. The East end of it is very narrow, and forces most traffic down to 20mph to prove your point gkgk, and is tense to cycle, but the West end of it is a veritable boulevard of open space. To join up to the 'QBC' and have segregated cycle lanes it would almost certainly need parking to be removed from at least one side of the 'east end'.

    Posted 11 years ago #

  8. Dave
    Member

    Or perhaps we could conclude that this particular road is way too wide to need a 20mph limit?

    So the wider the road outside a school is, the easier it is for kids to cross, hence the speed limit doesn't need to be as low?

    I hear the new M9 spur will be so wide, they aren't going to need to build bridges for pedestrians to get across :P

    It's easy to poo-poo the obvious lack of universal compliance within the south central 20mph pilot zone, but I prefer to look at it the other way around. For almost no money, with no road engineering and no enforcement the council has managed to deliver a speed reduction such that 50% of vehicles are doing 20-25mph.

    They could spend a squillion pounds narrowing the road to improve this further but I'd rather see them spend the money rolling the scheme out across town, and/or extending it to more through routes, before worring about the fact that they are not getting the ideal outcome.

    Ultimately, it can't practically be enforced or engineered, but it might be possible to engender social change (after all, most people don't refrain from drink-driving because they think they might get caught, at least not in the way that we mean when we talk about speeding).

    Posted 11 years ago #

  9. PS
    Member

    +1 to wot Dave said. Over time, people will learn how to drive in 20mph zones. As peds, kids, cyclists, animals, whatver start to behvae differetnly in these areas, then drivers will learn to be more alert and drive with care.

    I'm not a fan of all the pavement-widening, road-narrowing etc that we have in Edinburgh. In a number of places I would say that the road-redesigns have made the roads more hazardous for folks on bikes.

    Posted 11 years ago #

  10. chdot
    Admin

    "

    In a number of places I would say that the road-redesigns have made the roads more hazardous for folks on bikes

    "

    Yes - and in some cases without any obvious benefit to pedestrians.

    Posted 11 years ago #

  11. bdellar
    Member

    If you have a segregated cycle path, and then you narrow the road (not with a pinch point, but in general) then the traffic will slow down without affecting bikes.

    Posted 11 years ago #

  12. Wilmington's Cow
    Member

    Was thinking about this as we rode from Portobello to Musselburgh on Sunday.

    The road there used to be 40mph, with four lanes. Cars parked in the kerbside lane on both sides, but there was plenty space to occupy as a cyclist in what remained, and motorists, because of all the aprked cars, always stayed in the centre lane. Never felt a dangerous road (to cycle, I'd imagine not the easiest to cross as a pedestrian).

    Then they changed it. They narrowed everything down by putting a central hatch-marked 'lane', wih one traffic lane, and one parking lane on either side. The parking lane was narrower than the previous lane (that everyone parked in) meaning there was no longer a little refuge lane for cyclists, so you have to be in the traffic lane. The limit was dropped to 30mph, but because the overall width of the road has not been amended at all, and certainly the lane that the cars all drive in is the same width too, everyone still drives at 40mph. The only difference is that as a cyclist you now have to share that lane.

    I've never understood the change.

    Posted 11 years ago #

  13. Nelly
    Member

    WC - and islands which make it more hazardous to bikes.

    Posted 11 years ago #

  14. Wilmington's Cow
    Member

    I couldn't remember if the islands were there already or not. I'm assuming not given they're the width of the hatched area in the middle. Makes life easier for pedestrians, but if that was the aim then a couple of pedestrian crossings along the length would have worked much much better.

    Got passed far too closely at a couple of those islands on Sunday. It's just a shambles of a reorganisation really.

    Posted 11 years ago #

  15. chdot
    Admin

    "
    They narrowed everything down by putting a central hatch-marked 'lane'

    "

    Same with nice road through The Braids.

    Think it's to dissuade cars from running into each other.

    Would be wonderful with nice wide (segregated) two way cycle section next to pavement on view side - and a narrow two road on the golf course side.

    Or maybe a single track road with passing places!

    Too nice for a high speed traffic route.

    But ThisIsEdinburgh.

    Posted 11 years ago #

  16. kaputnik
    Moderator

    Islands and build-outs are generally put in to help pedestrians cross wider roads with higher speed limits in mroe safety, without providing them with a proper crossing which might endanger the "smooth flow of traffic".

    Of course "we" all know that they just create conflict zones that squeeze cyclists and cars together from both sides. Sadly our roads planners are oblivious to the fact.

    Posted 11 years ago #

  17. fimm
    Member

    I regularly use one road which has islands which are definitely there to slow traffic. (It is a long straight road with a 40 limit). I'm pretty agressive with taking the lane at the pinch points...

    Posted 11 years ago #

  18. sallyhinch
    Member

    you can easily put bike bypasses on pinchpoints - win win (for the bikes and the pedestrians) And once you'd done that, you might as well just put nice segregated tracks all the way along

    In parts of London they do seem to have an obsession with widening the pavement and narrowing the carriageway without putting any provision in for bikes and this seems to be the worst of all worlds. Even for the 'cruise at 20mph' crowd, nobody wants to be the rolling speedbump in a bus sandwich

    Posted 11 years ago #

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