[sustran] Re: Article in Guardian Newspaper

[Jack Mallinckrodt]

At 08:38 PM 3/29/03, Alan Patrick Howes wrote:
>I smell disinformation!
>
>Let's leave aside for the moment such questions as the safety and 
>environmental effects of 1,700 autos per hour vs 231 buses per hour, and 
>the effects on congestion on the rest of the traffic system - which are 
>major considferations.
>
>But even then - 11 persons per bus?! Our AVERAGE occupancy 
>(passenger-kms/vehicle-kms) here is 20.5, and that includes some minibus 
>routes. I would expect figures in Mumbai to be much higher. And if we had 
>bus lanes (dream on!) they would be in places where the occupancy was 
>higher still - perhaps 40 average and 50+ in the peak. Which even on 
>Jack's limited criteria changes the picture dramatically. Jack - is that 
>figure of 11 an overall US all-day average, or a figure for bus lane 
>sites, or what?

JM: I have found that there is a tendency to overestimate bus ridership 
when treated as an eyeball or off-the-cuff estimate. The figure of 11 
persons per bus is accurate.  It is from the DOT, FTA, US National Transit 
Database, 2001, for all times of day, all bus system opertors, all bus 
types, and is derived as
AVO = US Annual Bus Passenger miles / US Annual Bus Revenue hours
    = 1.83E11/1.65E9 = 11.09 passengers/bus.

That is quite an accurate number for the US average and has been about the 
same for the last ten years.  Comparable peak hour AVO numbers are not 
available. And As I said in my post, you'll have to use your own figures.

Peak hour loadings are certainly higher but they are so for both buses and 
for roads, so the comparison of day average persons/hour should  be 
indicative.

>
>You can certainly look at traffic flow like it was analagous to 
>electricity distribution - the more down the pipe the better - but that is 
>only a fraction of the proper picture if your goal is a "livable city". 
>Take a look at Jack's website Debi 
>(<http://www.urbantransport.org>www.urbantransport.org) and you will see 
>where he is coming from - then make your own judgement on the value of his 
>advice in your situation.

Evidently Alan, you decide what to believe based on the credentials of who 
says it.  I prefer, to make my arguments stand on their own valid data and 
logic. If that doesn't cut it with you, so be it.

Jack

>I don't know the full picture, but I suspect the problem in Mumbai is more 
>one of politics than planning.
>
>--
>Alan P Howes, Special Transport Advisor,
>      Dubai Municipality Public Transport Department
>aphowes at dm.gov.ae
><http://www.dubaipublictransport.ae/>http://www.dubaipublictransport.ae/
>Tel:    +971 4 286 1616 ext 214
>Mobile: +971 50 5989661
>-----Original Message-----
>From: Jack Mallinckrodt [mailto:mally at ieee.org]
>Sent: Sat, 29 March, 2003 21:16
>To: sustran-discuss at jca.ax.apc.org
>Cc: sustran-discuss at jca.ax.apc.org; gh7 at york.ac.uk; Matoff, Tom; vuchic; 
>Francis Vanek; Ritjavakhtar at aol.com; oeyvind.espe at ps.ge.com
>Subject: [sustran] Re: Article in Guardian Newspaper
>
>At 05:47 AM 3/29/03, Debi Goenka wrote:
>
>>We are trying to get some buslanes in Mumbai, and I would like to get 
>>some answers. The standard response to bus lanes in Mumbai is that the 
>>existing roads are not wide enough - my answer is that in such cases, 
>>perhaps such roads should be reserved exclusively for buses!
>JM: Well, maybe so, maybe not, but that should be based on comparison of 
>how many persons per day the bus system would carry vs for the 
>corresponding roadway. And that is exactly the same kind of calculation I 
>was illustrating for light rail.
>
>To compare bus vs automobile in the same way compute
>PPHbus = BPD x BAVO
>PPHauto = APD x AAVO
>where BPH = buses per hour past an average point along the busway
>       APH = Autos per hour past an average point along the road
>       BAVO = Average Vehicle Occupancy of a bus, persons/bus
>       AAVO = Average Vehicle Occupancy of an auto,persons/auto.
>The mode providing the higher PPH count is more productive.
>For example, using typical US numbers, if the roadway lane were to carry 
>1700 vehicle/hour at an average vehicle occupancy of 1.5 persons/vehicle, 
>the roadway would be carrying 2550 persons/hour. In the alternative, if 
>the average bus occupancy were 11 persons/bus, you would have to run 231 
>buses per hour, or one every 15 seconds to provide equivalent transport 
>volume, 2550 persons/hour.
>
>All the above numbers are typical for US, except for the 231 buses per 
>hour which is very high. You should make this calculation for your own 
>numbers for Mumbai. But for typical US numbers, it seems very unlikely 
>that a lane could be more productively used as a busway than as a regular 
>freeway or expressway lane.
>
>Jack
><http://www.urbantransport.org/>www.urbantransport.org
>


Jack
www.urbantransport.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://list.jca.apc.org/manage/private/sustran-discuss/attachments/20030329/f0e384c1/attachment.htm