tag:blogger.com,1999:blog-4063450658421522356.post4312060554858942207..comments2024-03-09T04:13:55.185-06:00Comments on Open PRT specification project: 159> Headway? I Don't Need No Stinkin' Headway!Danhttp://www.blogger.com/profile/16303568401426087509noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-4063450658421522356.post-7337588215924991862013-10-31T16:08:55.698-05:002013-10-31T16:08:55.698-05:00Don't know if you address another advantage to...Don't know if you address another advantage to zero-headway - significant reduction in wind-resistance. As a cyclist I can draft fairly easily at 30mph. Over extended stretches cars should snuggle up to each other as standard practice.JustMoneyhttps://www.blogger.com/profile/13499214592851731605noreply@blogger.comtag:blogger.com,1999:blog-4063450658421522356.post-51053772865652463732013-10-04T19:23:53.365-05:002013-10-04T19:23:53.365-05:00re "bogie trailer" problem: Well, that&#...re "bogie trailer" problem: Well, that's what I mentioned it for--to see if there was something I'd overlooked in the, oh, thirty seconds I spent thinking about it. :)<br /><br />Frankly, I don't think it's a particularly serious problem anyway. I only mentioned the trailer as a possible option for a city/utility/whatever that was going to make a big fuss about bumping. Dan didn't seem TOO upset about it, so I wasn't...qthttps://www.blogger.com/profile/09256501089151146138noreply@blogger.comtag:blogger.com,1999:blog-4063450658421522356.post-16205001443628961892013-08-28T11:09:35.356-05:002013-08-28T11:09:35.356-05:00qt, the problem with a sacrificial bogey like you ...qt, the problem with a sacrificial bogey like you describe is for steering with travelling in reverse. At diverge points, the sacrificial bogey may not choose the same direction as the bogey proper and jam/collide with the guideway. Reversing should not be used all that much, but it would be a shame to give up that capability.Andrew Fnoreply@blogger.comtag:blogger.com,1999:blog-4063450658421522356.post-38435858769064835102013-08-25T01:56:26.334-05:002013-08-25T01:56:26.334-05:00(continued)
I note that a PRT network could be ve...(continued)<br /><br />I note that a PRT network could be very heavily loaded because of the low cost of driverless traffic. We could e.g. have lots of low cost cargo traffic. Such vehicles could in principle fill all the gaps in the tracks. Those cargo vehicles (maybe carrying some bulk cargo like grain) could well stop and wait for other traffic whenever needed. We probably need different priority classes for this. Maybe one could also pay more for higher priority (if payments are used in the first place on public tracks).<br /><br />I can imagine some companies using the PRT tracks even as their storage space (from one factory location to another, or just running around). It may well be cheaper to send material to the PRT track than to build new storage space for it. The storage space could actually be also buffer tracks that have been built to take extra traffic off the main track in case of traffic jams. Or this could be a planned system where companies can be charged for the storage space (maybe in some huge storage areas, or just in small overflow buffers next to main crossings).<br /><br />From this point of view also the "headway space" could be seen as an additional buffer that could be easily filled. Any track could be filled up to its structural limits (some tracks may allow only one vehicle at a time on some lightweight track segments).<br /><br />In a system with different static and dynamic/changing priorities a good traffic policy may allow part of the traffic to travel full speed even if part of the traffic has to wait. The pain of traffic jams would thus not be spread evenly to all vehicles. Some vehicles might even get out of the way already when the probability of disruptions to some higher priority traffic grows. Having lots of (low priority) cargo on the system may thus also help others (humans) to have no (experienced) traffic jams at all.<br /><br />I note that different vehicles could have different preferences. Some might like to travel alone (to feel safer, to see the views, to allow flexible speed), some might want to save energy and form trains.<br /><br />One more observation. You could have also vehicles with one passenger compartment but with two bogies (on in the front, one in the back). That could give also better stability in high speeds if the bogies are really short. (This may change the bogie connection arm philosophy a bit.)Juho Laatuhttps://www.blogger.com/profile/15072614531174046945noreply@blogger.comtag:blogger.com,1999:blog-4063450658421522356.post-34594022402917130152013-08-25T01:55:05.084-05:002013-08-25T01:55:05.084-05:00Some short random comments follow.
In this articl...Some short random comments follow.<br /><br />In this article the traffic control seems to be fully distributed. It could be also hybrid. Instead of having one central computer, each section of the track or even each crossing could have its own computer. (Or maybe you planned even to make two vehicles negotiate between themselves (without any "track computers") which one enters a crossing first?) The idea is anyway that if I want, I could contact all the crossings at my planned track and ask for a slot at the planned time. If I get the slots, I would have an (almost) guaranteed track with agreed timing to my destination. This kind of a system would allow both preplanned trips and distributed recovery from whatever traffic jams. In the beginning there could be one central (track) computer. In the end all major crossings could have their own computer.<br /><br />Some dynamic route planning is needed in any case. A 100% preplanned system with fixed speed is not good. This is because of the possibility of unexpected problems (e.g. track blocked by a broken vehicle), need to change one's travel plan (e.g. after forgetting one's briefcase at home), and if we want to support just driving around the city, just too see the sights and to see what's going on.<br /><br />But dynamic dynamic route planning need not stop some vehicles having also fixed routes that take them to their destination in fixed time.<br /><br />Vehicles could have different priority. Highest priority is of course reserved for emergency traffic. Fixed planned routes may come next. Any (self made) changes in driving plans could lead to lower priority, and one could easily end up in a side track for a minute if one suddenly decides to take some congested route. Actually a good track has some extra space in the stations or in the form of sidetracks where one can push excess traffic when one has to. Better so than to stop or slow down all the traffic on the main track. Lower priority traffic could well wait.Juho Laatuhttps://www.blogger.com/profile/15072614531174046945noreply@blogger.comtag:blogger.com,1999:blog-4063450658421522356.post-50018414671281018552013-08-23T15:57:16.629-05:002013-08-23T15:57:16.629-05:00Concerning the bogie-touch problem in your PS, a s...Concerning the bogie-touch problem in your PS, a suggestion:<br /><br />How about a sacrificial bogie "trailer"? Basically a pair of bumpers connected by a crushable tube (or other structure), hung by an extremely simplified set of wheels and "towed" by the pod's bogie.<br /><br />Very lightweight, with no power or steering (it follows the main bogie through turns and switches like any other towed vehicle. The bumpers are tough enough to handle routine bumps and perhaps emergency pushes. The rest of the structure is designed to absorb major impacts and deform to spare bogie, pod, and passengers.<br /><br />Don't know how practical it is, but hey...qthttps://www.blogger.com/profile/09256501089151146138noreply@blogger.com