tag:blogger.com,1999:blog-3102538965694240940.post8691103809214689576..comments2024-03-27T12:53:39.298+01:00Comments on A view from the cycle path: The best traffic light solution for cyclists. Simultaneous Green scales to almost any size of junction. Safe, convenientDavid Hembrowhttp://www.blogger.com/profile/14543024940730663645noreply@blogger.comBlogger27125tag:blogger.com,1999:blog-3102538965694240940.post-68288746328717401912022-11-30T18:28:08.925+01:002022-11-30T18:28:08.925+01:00Unknown: agreed, though I hope we're both wron...Unknown: agreed, though I hope we're both wrong. One of the problems with expensive solutions is that the expense becomes an extra reason for them to be difficult to get built. It seems that there are only a handful of cyclops junctions at the moment so they're still very experimental and later ones may be improved and simplified.<br />Of course the UK has suffered for decades from the David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-31873201850290151212022-11-30T17:15:34.875+01:002022-11-30T17:15:34.875+01:00Thanks for the reply David- I'm not convinced ...Thanks for the reply David- I'm not convinced that Cyclops works in areas with high pedestrian footfall. They seem like an expensive, over-engineered solution.Anonymoushttps://www.blogger.com/profile/18052393905229203938noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-45072969413114759402022-11-25T14:52:52.420+01:002022-11-25T14:52:52.420+01:00Unknown: I'm afraid I've not been followin...Unknown: I'm afraid I've not been following what's going on in the UK so I can't tell you whether it's more likely that Simultaneous Green is allowed now. Probably not, I would guess, as no-one seemed to be fighting for the changes which be required to make it possible. There is another design called CYCLOPS which has been built a couple of times in the UK and I think the David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-38818509641376327942022-11-25T13:28:31.252+01:002022-11-25T13:28:31.252+01:00Hi,
I'm looking into Simultaneous Greens as I...Hi,<br /><br />I'm looking into Simultaneous Greens as I'm convinced that they are the cheapest, simplest and safest design available. Do you know whether anything has changed since you wrote this blog that makes it any more likely that their use is permitted within the UK?Anonymoushttps://www.blogger.com/profile/18052393905229203938noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-35699462612837214692015-07-29T09:22:54.520+02:002015-07-29T09:22:54.520+02:00Childbacktandem: Some people go through red lights...Childbacktandem: Some people go through red lights, but they're a minority. Collisions are the result not only of people being careless but also of infrastructure which is designed in a way which results in careless behaviour quickly leading to dangerous situations.<br /><br />The simultaneous green design solves these problems to a greater degree than other traffic light junction designs David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-85944691858895910962015-07-27T17:36:39.010+02:002015-07-27T17:36:39.010+02:00Lots of people do go through red lights (drivers a...Lots of people do go through red lights (drivers as well as cyclists) and in the UK pedestrians are permitted to. Under any system, collisions are almost always a result of at least one party being careless or breaking the rules. <br /><br />The more motor vehicles, the faster the speeds and the more complex the junction, the longer the cycle times and the bigger the temptation. (This is not a Childbacktandemhttps://www.blogger.com/profile/13885323778319768001noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-45487782905382127422015-07-27T15:27:55.587+02:002015-07-27T15:27:55.587+02:00Childbacktandem: Simultaneous Green junctions aren...Childbacktandem: Simultaneous Green junctions aren't merely "safe enough", they're just about the safest design of large junction possible. This is because ALL motor vehicles are at a standstill behind a red traffic light when cyclists use the junction. Therefore there is no risk whatsoever. No chance for "masking" or any other effect. This is why there have been David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-87550124980270896592015-07-27T15:14:44.119+02:002015-07-27T15:14:44.119+02:00I am interested that you appear to feel that an al...I am interested that you appear to feel that an all-green makes crossing major multi lane junctions safe enough. Can you comment more on these larger junctions please? <br />'Masking' collisions are a common problem in the UK. I mean the case where a motor vehicle hits a cyclist entering the crossing because they are masked from each other by another vehicle (especially likely if it is Childbacktandemhttps://www.blogger.com/profile/13885323778319768001noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-30978042516279949692014-10-10T15:30:49.298+02:002014-10-10T15:30:49.298+02:00Thedoc: Sadly, I think you simply do not understan...Thedoc: Sadly, I think you simply do not understand.<br /><br />"All red is not practical" - This is because you are looking at continuing with the same situation as you have and not at real change. The combination of making cycling more attractive and moving driving routes away from where the junctions are which cyclists use and you have to deal with considerably fewer cars.<br /><br /David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-47904678510276572412014-10-10T15:00:11.071+02:002014-10-10T15:00:11.071+02:00Ill just agree to disagree on some of this for now...Ill just agree to disagree on some of this for now as its like a game of tennis but in short.<br /><br /><br />"There is no capacity problem for drivers because green phases are short." <br />Yes there is purely because you are having any green phase at all. The area's I am talking about do not want an all red traffic phase of any kind because it kills the capacity. All red is Thedochttps://www.blogger.com/profile/01427430568416977051noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-63108955438170678482014-10-10T11:15:15.707+02:002014-10-10T11:15:15.707+02:00Thedoc: I'm afraid your reply is riddled with ...Thedoc: I'm afraid your reply is riddled with misconceptions.<br /><br />For a start, you've misunderstood how much time is required for Simultaneous Green. There is no capacity problem for drivers because green phases are short. It takes barely any longer for a cyclist to cross a road diagonally than to go straight across. If you allow diagonal cycling, no second crossing and associated David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-54208722130779490982014-10-09T11:11:57.000+02:002014-10-09T11:11:57.000+02:00"Don't forget, when we have all round tou..."Don't forget, when we have all round toucan stages, there is nothing (in law) to stop anyone walking or riding the diagonal."<br /><br />Hello there. I liked your blog.<br /><br />True we have the all round toucans although we do try to avoid all red ped or cycle phases as much as possible on London streets purely because of the impact on capacity. <br /><br />That is the main Thedochttps://www.blogger.com/profile/01427430568416977051noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-35506921025207522332014-10-06T19:31:22.735+02:002014-10-06T19:31:22.735+02:00Thedoc - it would work, but it *just* needs a bit ...Thedoc - it would work, but it *just* needs a bit of will.<br /><br />Don't forget, when we have all round toucan stages, there is nothing (in law) to stop anyone walking or riding the diagonal.<br /><br />I know people are resistant to change and I wonder if it is they are just pro-traffic or scared that something might just work and so break the status quo.<br /><br />I do know how The Ranty Highwaymanhttps://www.blogger.com/profile/17361350433158148025noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-10110962428721893452014-10-06T14:25:06.976+02:002014-10-06T14:25:06.976+02:00Quite direct in your manner of responses. Sound li...Quite direct in your manner of responses. Sound like you think I am stuck in the dark ages and are not pro bike. Far from it. I am a progressive engineer who is very pro cyclist and is always challenging legislation but am also a realist. You talk as if we have a choice in the matter. <br /><br />We are so regulated over here it's not funny. I'll keep thinking that way until the DFT lets Thedochttps://www.blogger.com/profile/01427430568416977051noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-66441317198014876182014-10-06T09:52:51.099+02:002014-10-06T09:52:51.099+02:00Thedoc: The "not in a million years" att...Thedoc: The "not in a million years" attitude is the real problem, not the width of your roads.<br /><br />Many of the example "before" photos on this blog and elsewhere are precisely of the most busy city streets, where people could at one time see no alternative other than to continue to allow more and more motor vehicles.<br /><br />Just as there is "no space for cycleDavid Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-28951526197599806812014-10-04T10:06:45.695+02:002014-10-04T10:06:45.695+02:00Hello.
Sorry I am struggling from the link you se...Hello.<br /><br />Sorry I am struggling from the link you sent to see any before an after photos of anywhere except where streets have been transformed to low motor vehicle use. Not sure where you were trying to point me towards but that link cannot really translate to junctions and roads on the TLRN where you are never going to reduce the traffic in a million years.<br /><br />As I said before IThedochttps://www.blogger.com/profile/01427430568416977051noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-57897871605932507462014-10-03T17:44:34.953+02:002014-10-03T17:44:34.953+02:00Thedoc: What on earth makes you think that all jun...Thedoc: What on earth makes you think that all junctions in the Netherlands have lots of space ? They don't. Several of the examples above are in very small junctions, as I pointed out in my last response.<br /><br />In the Netherlands there also used to be people who thought that there was "<a href="http://www.aviewfromthecyclepath.com/search/label/notenoughspace" rel="nofollow">not David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-60320067437413153352014-10-03T12:15:56.460+02:002014-10-03T12:15:56.460+02:00Yes I stand by that because the junctions and area...Yes I stand by that because the junctions and areas in London that would benefit from this just simply don't have the space. Its all great where you have plenty of room to put a cycle track in and lots nice big footways but you cycle through the city and you are lucky if you can for a 1.2m lane in next to a 2m footway, never mind a track. <br /><br />Am not saying the design sucks. Far from Thedochttps://www.blogger.com/profile/01427430568416977051noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-58349703454719664732014-10-03T09:46:49.669+02:002014-10-03T09:46:49.669+02:00Thedoc: Are you seriously trying to suggest that w...Thedoc: Are you seriously trying to suggest that what works exceptionally well in some of the highest cycling modal share cities in the world will somehow not cope with the far smaller number of cyclists in <a href="http://www.aviewfromthecyclepath.com/search/label/london" rel="nofollow">London</a> ? Of course it will !<br /><br />This is a remarkably non site-specific design - hence the wide David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-69379383865299046762014-10-03T09:23:12.946+02:002014-10-03T09:23:12.946+02:00This whole A and B thing falls down here and only ...This whole A and B thing falls down here and only makes sense if there is only one cyclist going in each direction. If A and B go at the same speed the will avoid each other. The other guys behind them won't though. This is a very site specific type design and you would really struggle to get it to work on a site in London with high cyclist. I am not trying to be negative here but It would Thedochttps://www.blogger.com/profile/01427430568416977051noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-34113934800729951402014-06-26T22:12:24.498+02:002014-06-26T22:12:24.498+02:00HB: I've not seen one where pedestrians can cr...HB: I've not seen one where pedestrians can cross diagonally as well and I doubt that it would work well.<br /><br />While SG junctions decrease conflict between cyclits and other modes, letting pedestrians cross diagonally at the same time would create conflict. It would have all the problems of <a href="http://www.aviewfromthecyclepath.com/search/label/shared%20use%20paths" rel="nofollow">David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-67650672742283174702014-06-26T21:38:09.035+02:002014-06-26T21:38:09.035+02:00David, Are there any SG junctions that do allow pe...David, Are there any SG junctions that do allow pedestrians to cross diagonally as well? HBhttps://www.blogger.com/profile/12803252648424411894noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-3163110859629771722014-05-31T13:05:53.118+02:002014-05-31T13:05:53.118+02:00Stewart: Thank you for your correction. You're...Stewart: Thank you for your correction. You're right that it made no sense at all as written (though hopefully the picture made clear what was intended). I've corrected and expanded on the text.David Hembrowhttps://www.blogger.com/profile/14543024940730663645noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-20424939813841743602014-05-30T20:31:28.935+02:002014-05-30T20:31:28.935+02:00David - I think the editing process went wrong in ...David - I think the editing process went wrong in the pedestrians section of the article:<br />However, provided that pedestrian crossings are outside of the normal pedestrians crossings can operate in all directions at the same time as cyclists are using the simultaneous green crossing.<br />regards<br /><br />Stewart B<br /><br />Anonymoushttps://www.blogger.com/profile/10363865126813057311noreply@blogger.comtag:blogger.com,1999:blog-3102538965694240940.post-68959334874102542432014-05-08T16:41:24.021+02:002014-05-08T16:41:24.021+02:00good stuff.
i suppose it is an extension of the &q...good stuff.<br />i suppose it is an extension of the "all-green" pedestrian junctions, such as some in Japan, at least on in the shopping district of Edinburgh, and at least one in Newquay, Cornwall - the last mentioned-two, I have used myself :-)Pedal Pusherhttps://www.blogger.com/profile/02912765232379572267noreply@blogger.com