Tan Kin Lian's Blog: Space in MRT trains

Sunday, July 04, 2010

Space in MRT trains

Hi Mr. Tan
Recently there is a debate going on whether the SMRT trains in Singapore are overly crowded or not. The SMRT doesn't think very much of it as evidenced in their CEO's untactful remarks, whilst practically everyone blogging on the internet curse and swear at how bad the situation had become.

Looking at the case again, I just discovered that everything hinges on a statistic which is provided by SMRT Quote:...This averages 3.8 passengers per sq m, lower than that of major cities like London..... Unquote.

So 3.8 passengere per sq m is the agreed benchmark. I have no problem with that. But look at the word AVERAGE. Therein lies the solution to the puzzle. It's not about the number 3.8 neither is it about the techie word crushload. It's about AVERAGE.

AVERAGE is a very dangerous concept if not properly managed. If the annual salary of the PM is $3 million and the annual salary of the rest of the 9 ordinary workers in the PMO (PrimeMinister's Office) is $50,000 then mathematically the average annual salary of the people in the PMO is $305,000 per person? In statistical theory there are median, and mode, standard deviation, etc to refine the imperfect concept of averaging. In the real world, we also need to know more about the model used for "averaging".

How does SMRT calculate its AVERAGE crush load? Is it over time average between peak period and non peak period per station basis? How many stations are selected? Which are the stations selected for the averaging? Are newer stations which have lower load factor bundled together for averaging?

Statistics is a powerful tool which can often lead to wrong conclusions. Sometimes it is so powerful that it can be used as a tool to make one feel complacent and look good. And those who ignore the possibly distorted conclusions might be told to make other choices because the sysem is just doing fine - on "average".

rex

20 comments:

Anonymous said...: This is a good read,thanks.
In this case,MRTC's CEO is using the number power to mislead the commuters.Nowadays,even if one try to board the trains during off-peak hours you could see a huge mass of commuters rushing into the trains.
It is hope that the Singapore media could arrange with the top rung of the transportation providers to try out for themselves then they can understand the whole situation and improve upon them.

a commuter; July 04, 2010 12:24 PM
Anonymous said...: SMRT and its CEO are learning fast, from our politicians!

Remember Mah Bow Tan had also used a particular base year to illustrate that house prices have not outstripped income growth. But this was debunked by one Hazel Poa, an upcoming opposition member in her blog http://hazelpoa.blogspot.com/

Statistics has become a good tool to be interpreted in one's favour, though careful selection (or omission) of the right numbers! Hence it is often used by ruling politicians and the mainstream media under their control for positive publicity.

But they fail to realise this can backfire on them with an educated and informed electorate and helped by the Internet.; July 04, 2010 12:40 PM
Anonymous said...: Rex,
I truly agreed that statistics is a powerful tool. The conclusions drawn can be biased; depending on what you want to reveal or hide.
I read with interest on the recent article on "$3,100 median income goal". How reliable is this 3.1k?; July 04, 2010 1:09 PM
Createwealth8888 said...: When Bill Gates steps into a Pub, everybody in the Pub becomes an average Milliionare. Probably most people has heard this joke.; July 04, 2010 1:18 PM
Anonymous said...: On the one hand, policy makers often benchmark performance to 'other' cities,companies etc. While on the other hand, they will take, conviniently, a factor such as 'Singaporeans are not the same'.

Shifting goal posts to suit their arguements.

Unfortunately, more than half of our population is left with issues that require their attention and thus will not be aware of nuances of 'average' etc..

Eventually the truth will prevail.
I believe in cause & effect.; July 04, 2010 1:25 PM
Lye Khuen Way said...: Guess who aced his Statistics ?
We mortals must not expect too comfee a ride during 'peak hours' : can always choose a later time : buy a car : walk : take taxi/ bus , no ?
Ultimately, who privatise the MRT , then point fingers whether it is a service level issue or National security issue to the "private" entity ?
SMRT incidentally is >> 50% Termasek owned.; July 04, 2010 2:13 PM
Wealth Journey said...: It's very easy to determine crush load.

It's just a visual check like those captured here.

http://www.youtube.com/watch?v=b0A9-oUoMug&feature=related

:); July 04, 2010 2:37 PM
Anonymous said...: Statistic in commercial world is created to favour the one who pays to do it, period. SMRT has a limit to increase the frequency of its service. 2 minutes is the shortest according to people who work in this line. When the platform was designed to hold 6 cars, that's it unless the platform is to be enlarged.

Mr. Tan, can you conduct a survey to see how many have benefited from the new fare by distance formula? For me, all my trips ended up an increase, one as much as 17%. This is another way to cheat the public. Thanks

Loh; July 04, 2010 6:14 PM
Anonymous said...: I think MRTs are less crowded now than say in the period from 1995 to 2001.
I know this because I bought a car in 2001 and recently sent my car to the workshop for an extended period. Took MRT and bus.

Less waiting time and less packed. Used to be 1.5 hrs to work, now only 1 hour.; July 04, 2010 7:08 PM
Anonymous said...: I suggest MRT to have KPI of:
"At least 95% of passengers waiting at the platform who choose to board the train during peak hour at their 1st attempt are successful in doing so."; July 04, 2010 7:25 PM
Michael said...: I remembered that when the late President Ong Teng Cheong was the then Minister for Communications in early 1980, he convinced the cabinet to choose the MRT system instead of all bus-system although the latter is much cheaper in costs. Mr. Ong, after his overseas study trips on the public transport system, he had decided on the MRT system which could bring along 'a better life' for all of us. Word of 'quality' was in his mind. The thought of 'cheap' or 'average' was not a factor being considered in this big decision(to build a MRT at the costs of S$5 billion for the phase one) that would greatly enhance our quality of life. Many Singaporeans missed him and respected him as one of the 'Quality Minister' but on 'Average' pay. Comrade Ong did not understand 'betterest'. He had been 'better-rest' since 8th February, 2002.; July 04, 2010 9:42 PM
Anonymous said...: looks like to SMRT or even the govt in general, Statistics is the only tool that they use rather than taking a real look at situations themselves and experience it.; July 05, 2010 12:33 AM
Anonymous said...: When you have more than 1 million of foreign workers in Sgp ie 1/4 of the total population, what transport do they take? Private cars? Taxis?

None of the above. It is public transport as it is cheaper and they need to stretch their low income. More and more PMET sitting at home while more foreign workers take MRT. The number of middle-aged PMET sitting is far less than the foreign workers taking over their jobs due to lower salary.

What was the Govt reaction?

They did not hear. Deaf frogs are already deaf the moment they are voted in by us. Now we, the PMET are suffering while the foreign workers wonder how come stupid Singaporeans still vote in the Govt who gave their jobs away to foreigners.

This can only happen in Singapore because we are just too trusting of this Govt and continue to believe it was not their fault. Imagine they draw $254,000 a month and we, the PMET, continue to wait for rejection letters and wondering what tomorrow will bring.

No eyes to see.....; July 05, 2010 12:55 AM
Anonymous said...: When you put one foot in the oven and the other in the refrigerater, you are on the average warm.; July 05, 2010 8:53 AM
Anonymous said...: Talk so much still no solution right? In the meantime, if you can afford to leave the house early, do so, as the train are not so packed.; July 05, 2010 1:37 PM
Anonymous said...: It is my opinion that the reason why people like the SMRT CEO and others can make questionable remarks so frequently is because they believe they can get away with it as we can do nothing about it.

It's got to do with who is perceived to have the power that cannot be ignored.; July 05, 2010 2:57 PM
Anonymous said...: we need another scholar to appear and give us solutions! that's the way the govt/ministries/whatever-govt-related-org works! hahaha; July 05, 2010 3:22 PM
Anonymous said...: I think this idea should probably be feasible to increase capacity. Extend the train length by one or two more carriage at each end, assuming the motor is powerful enough. The extra carriage will extend out of the station platform hence will not open its doors. Passengers in the extra carriage will have to enter/exit through the other carriages.; July 05, 2010 10:08 PM
Anonymous said...: rex comments on anon july5 10.08pm post,

interesting proposal.. however, since the extra carriage can't unload the passengers as quickly, the entire train will have to remain in the station longer! That will have an impact on the entire scheduling of stop-times of trains in the whole route.. the commuters have to wait longer before the next train arrives.
So it is the same impact, even if the train is more empty you have to wait longer. back to the drawing board...?

rex; July 06, 2010 8:32 AM
Lim S said...: Sold my SMRT shares on the day of CEO comments. a law should be in place where all civil servants including Ministers and transport works to take 1 days of public transport a week then within 1 month, there will be major improvement.

the stewards they hire dont do much work unlike the Japanese professionals who ask people to move in.; July 08, 2010 2:36 PM