rincew1nd
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Junior Under-wizzard of quiz
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Post by rincew1nd on Sept 24, 2015 7:23:22 GMT
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Post by 100andthirty on Sept 24, 2015 7:31:52 GMT
An interesting theory with some conclusions that will need loads of testing. The use of the tube, particularly, is so complex that the link only between road and tube is VERY simplistic.
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class411
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Post by class411 on Sept 24, 2015 7:32:40 GMT
I just read that before coming here.
I wonder if they properly accounted for interchange timing. It can vary extremely widely and sometimes makes a longer journey on one mode a better bet, even if the actual segment times add up to less on two or more modes.
I've never seen any tables of estimated average interchange times, and given that they did not use any actual passenger data, I'm dubious as to whether it was considered - at least with any accuracy.
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Post by alang on Sept 24, 2015 8:37:09 GMT
I just read that before coming here. I wonder if they properly accounted for interchange timing. It can vary extremely widely and sometimes makes a longer journey on one mode a better bet, even if the actual segment times add up to less on two or more modes. I've never seen any tables of estimated average interchange times, and given that they did not use any actual passenger data, I'm dubious as to whether it was considered - at least with any accuracy. Indeed it is pretty clear from Dr Barthelemy's reported remarks that his team's study deliberately chose great simplifications to make it practicable. The spurious precision of the "13mph" optimum is almost cetainly an journalistic artefact - "Giving exact numbers is a tricky thing" is a polite way of saying "do not publish these numbers because they are meaningless", but the writer clearly ignored the warning. What the study shows is that, as many have known for a long time, in complex systems optimising each part separately can have bad effects on the whole system. It would be good if it caused planners to consider these things more carefully, but I don't hold out very much hope of this. Alan |
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Deleted
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Post by Deleted on Sept 24, 2015 9:45:25 GMT
Forgive me for being simplistic but slower trains = less trains/hour = less capacity = more crowded stations!
XF
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Post by rsdworker on Sept 24, 2015 10:27:00 GMT
yes that's why i think slower train is more worse than fast trains - can result in crowding and switching to cars/motorbikes/cycling/bus
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Post by trt on Sept 24, 2015 12:52:58 GMT
The study didn't take into account the time taken to change modes. In London that's about 60 minutes as you drive round and round in circles around a one-way system of backstreets trying to find a parking space nearer to the tube station than your ultimate destination.
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Post by peterc on Sept 24, 2015 13:51:43 GMT
So, if you speed up the trains more people switch from driving to going by train. A side effect is that you get more wives picking up hubby at the station and longer queues at the bus stop for the last leg of the journey. Perhaps Prof Batty can give us an estimate of when Mafeking will be relieved?
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Deleted
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Post by Deleted on Sept 24, 2015 15:16:11 GMT
Forgive me for being simplistic but slower trains = less trains/hour = less capacity = more crowded stations! = even slower trains |
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Post by philthetube on Sept 24, 2015 15:22:49 GMT
Slower trains could mean trains operating closer together as smaller gaps needed between trains because of less stopping distance needed. not entirely sure where that leaves the numbers.
More people switching to cars because of slower trains would also skew the numbers.
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Deleted
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Post by Deleted on Sept 24, 2015 15:32:26 GMT
Slower trains could mean trains operating closer together as smaller gaps needed between trains because of less stopping distance needed. not entirely sure where that leaves the numbers. More people switching to cars because of slower trains would also skew the numbers. This is true, with (I'm sure) substantial signalling modifications and subject to rolling stock availability, but then you start giving yourself RORI problems, for example. |
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Post by norbitonflyer on Sept 24, 2015 15:37:53 GMT
Slower trains could mean trains operating closer together as smaller gaps needed between trains because of less stopping distance needed. not entirely sure where that leaves the numbers. . Well, yes - but in the limit you have the trains parked nose to ail and not moving at all. 0tph but plenty of room for everyone! Slower trains also mean you need more of them to achieve the same throughput. This was why the post-Hatfield speed restrictions caused such havoc - if a train is running at half its scheduled speed, it can only make three round trips instead of six. |
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Deleted
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Post by Deleted on Sept 24, 2015 16:37:44 GMT
Might as well have a fast travolator then lol
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Post by brigham on Sept 24, 2015 17:11:34 GMT
"Maybe making Crossrail as fast as possible isn't the best solution in terms of global congestion," Dr Barthelemy commented.
Too true. A few MPH faster through London could cause havoc in downtown Tokyo!
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Post by John Tuthill on Sept 24, 2015 17:58:12 GMT
Might as well have a fast travolator then lol Or a red flag with every ticket?  |
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Post by theblackferret on Sept 24, 2015 18:55:11 GMT
"Maybe making Crossrail as fast as possible isn't the best solution in terms of global congestion," Dr Barthelemy commented. Too true. A few MPH faster through London could cause havoc in downtown Tokyo! And just look what can happen when the train schedules down there get screwed up! It's OK for Prof Pat Pending & his Convert-A-Car, we don't even have Raymond Burr to help us out now! |
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Post by superteacher on Sept 24, 2015 20:32:41 GMT
Good grief, don't show that article to Met line users!
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Post by spsmiler on Sept 24, 2015 22:40:49 GMT
Best not to show this to Central and Victoria Line users - the thought of travelling as slowly as the other tube lines would be irksome.
Still it could be even worse... my thoughts turn to the lack of speed of Overground trains when entering stations.
Some years ago I used to work in Hendon and to my dismay the journey from Gants Hill to work via Hendon Central took even longer than the rush hour traffic on the A406 North Circular Road.
Simon
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