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Busway speed limits

Started by somebody, December 13, 2009, 19:54:34 PM

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somebody

Used the Northern Busway today, and I paid attention to the speed limits. 

  • 40km/h outside of stations is unacceptable, and 50km/h isn't much better. 
  • It's 40km/h along Countess St, which is the same speed as applies to amatuer drivers around primary school kids.  Are BT employing children who might run out in front of a bus without looking? 
  • 50km/h applies between QUT KG & Normanby, apparently because of a moderately sharp bend near Normanby.  Advisory speeds are considered completely adequate for roads, why not the busway?  If they seriously think that the speed restriction is required, why's it apply all the way between the bend and QUT KG?
  • IIRC it was 60km/h between RCH Herston & QUT KG.  But why not 80km/h? It's 90km/h on parts of the SE Busway, what's that different here?
  • While we're on the topic, the 20km/h in QSBS appears to be because of the "snake", but that kicks in way too early
  • 40km/h is too slow through stations.  I personally wouldn't have a problem with 60km/h through stations, as it's not like anyone's likely to run across in front of a bus.  But 50km/h wouldn't be all bad as a compromise
Seriously, the busway's value is reduced by the low speed limits.  Fix that, and the busway would be faster than driving, but it's not now.

Perhaps I'm still a nutter.

#Metro

I think the design needs to be looked at.
Cars can go at speeds of 100-110 km/hour on freeways. Why can't busways be designed for that?

In Adelaide, their buses can go 100 km/hour and the driver can read a book because it is guided by a track.
Negative people... have a problem for every solution. Posts are commentary and are not necessarily endorsed by RAIL Back on Track or its members.

beauyboy

The 90kmph limits are applied for the same reason why Vlines Velocities do not do 200kmph instead of there current 160.
Benefit to cost ratio is minimal.

As for increased speeds throught stations. I can tell you right know I would not support that. The risk of a bus pulling out on a express is not worth it and the lenght of the merge from each station is not long enough. Watch Culture Center a few afternoons and you will quickly understand what i mean.

Donald
www.space4cyclingbne.com
www.cbdbug.org.au

dwb

Isn't it to reduce the impact of bunching at stations?

... and passenger comfort.

.... and probably Australian Standards is why they use limit signs not recommendations. Afterall, they're not recommendations, they're limits, ie maximum of 40km/hr through stations but driving to the conditions.

somebody

Quote from: beauyboy on December 14, 2009, 18:32:59 PM
The 90kmph limits are applied for the same reason why Vlines Velocities do not do 200kmph instead of there current 160.
Benefit to cost ratio is minimal.

As for increased speeds throught stations. I can tell you right know I would not support that. The risk of a bus pulling out on a express is not worth it and the lenght of the merge from each station is not long enough. Watch Culture Center a few afternoons and you will quickly understand what i mean.

Donald
I wasn't complaining about the 90km/h limits, but comparing those limits to the 60km/h and less on the Northern busway.

So, if one station has 40km/h and another 50km/h, making them both 50km/h would be unnacceptable to you, but leaving the one that is currently at 50km/h is ok?  IIRC at least one station has a 50km/h limit through it.

Or were you talking about my whinge about the 20km/h in QSBS.  What I said was that it is for the "snake" but kicks in way before that.  Your counter point doesn't apply here.

Quote from: dwb on December 15, 2009, 16:28:51 PM
Isn't it to reduce the impact of bunching at stations?
Reducing the impact of bunching doesn't seem to be a sensible reason to me.


Quote from: dwb on December 15, 2009, 16:28:51 PM
.... and probably Australian Standards is why they use limit signs not recommendations. Afterall, they're not recommendations, they're limits, ie maximum of 40km/hr through stations but driving to the conditions.
Well advisory signs are used on the roads, and have been for donkeys years.  Why are you saying that there would be an Australian Standard against them on the busway?

dwb

My laymans understanding of speed recommendations is that they're generally limited to "that" corner... for the busway it seems sections of busways have different speeds. Its my understanding that different bits of busway are built to different standards given the locational constraints. Despite this, as far as I know, ALL stations are 40km/hr though them except for perhaps KGS and QSBS (bus station not busway station).

You might like to consider bunching between Mater and South Bank busway stations and the effect the 50km/hr speed limit through the section between the stations has on it and passenger comfort (its not only NB that has slower sections). In my mind at least it is a good idea, especially as raising it would only possibly save 5seconds or so, and reduce the comfort of the acceleration and braking patterns of buses using these stations.

stephenk

Quote from: somebody on December 13, 2009, 19:54:34 PM
  • IIRC it was 60km/h between RCH Herston & QUT KG.  But why not 80km/h? It's 90km/h on parts of the SE Busway, what's that different here?
There is a non traffic signalled reversing loop at QUT KG. Maybe 60km/h allows for a safe braking distance for buses on the busway if they happen to come across a reversing 66?
Evening peak service to Enoggera* 2007 - 7tph
Evening peak service to Enoggera* 2010 - 4tph
* departures from Central between 16:30 and 17:30.

dwb

My point was that I think it is 90km/hr on the SET only where there are large distances between stations with no on or off ramps. Places where the stations are close to one another or there are ramps are slower. But I'm not a transport engineer who deals with safety standards day in day out so I can't really respond to your question!

somebody

Quote from: stephenk on December 15, 2009, 17:34:43 PM
Quote from: somebody on December 13, 2009, 19:54:34 PM
  • IIRC it was 60km/h between RCH Herston & QUT KG.  But why not 80km/h? It's 90km/h on parts of the SE Busway, what's that different here?
There is a non traffic signalled reversing loop at QUT KG. Maybe 60km/h allows for a safe braking distance for buses on the busway if they happen to come across a reversing 66?
Don't think so, isn't that still within the "station" speed restriction zone of 40-50km/h?

Quote from: dwb on December 15, 2009, 17:41:14 PM
My point was that I think it is 90km/hr on the SET only where there are large distances between stations with no on or off ramps. Places where the stations are close to one another or there are ramps are slower. But I'm not a transport engineer who deals with safety standards day in day out so I can't really respond to your question!
Possibly, I might have to pay more attention next time.

Andrew

Quote from: somebody
Used the Northern Busway today, and I paid attention to the speed limits. 

  • 40km/h outside of stations is unacceptable, and 50km/h isn't much better. 
  • It's 40km/h along Countess St, which is the same speed as applies to amatuer drivers around primary school kids.  Are BT employing children who might run out in front of a bus without looking? 
  • 50km/h applies between QUT KG & Normanby, apparently because of a moderately sharp bend near Normanby.  Advisory speeds are considered completely adequate for roads, why not the busway?  If they seriously think that the speed restriction is required, why's it apply all the way between the bend and QUT KG?
  • IIRC it was 60km/h between RCH Herston & QUT KG.  But why not 80km/h? It's 90km/h on parts of the SE Busway, what's that different here?
  • While we're on the topic, the 20km/h in QSBS appears to be because of the "snake", but that kicks in way too early
  • 40km/h is too slow through stations.  I personally wouldn't have a problem with 60km/h through stations, as it's not like anyone's likely to run across in front of a bus.  But 50km/h wouldn't be all bad as a compromise
Seriously, the busway's value is reduced by the low speed limits.  Fix that, and the busway would be faster than driving, but it's not now.

Perhaps I'm still a nutter.


The main reason why the busway has reduced speed limits, primarily on corners and stations is to do with line of sight and more generally speaking, safety.  Being a regular user of the busway, I can sympathise with your frustration.  To address some of your specific items:

  • the main reason Countess St has a 40km/h limit is because that it is an area of high traffic with entering and exiting traffic and pedestrians accessing the meal room.
  • The curve between QUT and Normanby is not exactly moderate.  It is moderate at 50.  Taking a bus round there at 70 in the wet when your front wheels could potentially lose traction (particularly if you don't have a gas pod sitting over your front axle... and even then it) would be dangerous.  Also all tunnels on the busways are no more than a 50km/h limit with some being less.
  • Between RCH & QUT is mainly because of line of sight.  If you are doing 90 clicks with a standing load and you whizz round a blind corner to a stationary broken down bus, it will probably not end well.  When everything is good and working, higher speeds are ok but the reason is that they plan for problems to an extent.  Beleive it or not, in some speed monitoring done in the past year, a vehicle was clocked at 97km/h outbound through Southbank busway station.  Now it could have been an Ambulance or a Police car under lights and sirens.  But maybe not.  The monitoring did not specify.  But I can tell you round that bend into the tunnel at Southbank at that speed would be suicidal.  You cannot see round the corner.
  • As for Queen St Bus Station, the main hazard here is that buses coming from Victoria Bridge can have their lane "fouled" so to speak by a bus coming the other way who is exiting a stop and overtaking a parked bus in front.  That's one main reason, I would imagine, for the 20km/h.
  • As for speeds through the stations, I would personally like to see them relaxed as long as no person or vehicle is present on the roadway upon entering the station.  That way safety is not compromised.  As for pedestrians, they are what you'd call a known unknown.  It is not uncommon for pedestrians to cross the Busway or even start to walk along it (or skateboard along it as some kids near Garden City started doing the other day)
As for the busways value being reduced by lower limits, it depends on how you look at it.  The busways, I do not believe, were designed to be faster than off peak traffic.  I think they were, however, designed to increase the reliability of the bus service.  With this goal in mind, I believe for the most part that the Busway has achieved this goal.  Also a bus at 80 or 90 is faster than a car crawling on the freeway at 40 in peak hour.

Anyways I hope this answers some of your questions.

Regards

Andrew
Schrödinger's Bus:
Early, On-time and Late simultaneously, until you see it...

somebody

Ok, RCH-QUT line of sight, I can see how that could be an issue.

I can't see how any of your other points counter my points though.  Sorry.  QSBS, the 20km/h kicks in only after you have entered the bus station so I don't see how this counters my point.

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