Here are the relevant figures to compare the North South Line and the Downtown Line. I took it from the speech by the Transport Minister Khaw Boon Wan 14 Nov 2017.
https://www.todayonline.com/singapore/comparing-singapores-newest-and-oldest-mrt-linesQuote:
I asked the Land Transport Authority (LTA) to make a comparison between the two lines and highlight the differences. Thirty years separate these two lines and some of the differences are stark, to be expected.
First, the first phase of the North-South Line, cost us around $2.7 billion to build, or $4.4 billion in today's dollars. The Downtown Line cost us close to $21 billion.
The cost per kilometre has gone up from $160 million to $490 million. Each kilometre will therefore cost half a billion dollars - partly due to technology and partly due to inflation.
Second, the North-South Line is about 40 per cent underground while the Downtown Line is completely underground.
Third, the North-South Line has 26 stations, of which eight, or 30 per cent are interchange stations. The Downtown Line has 34 stations, of which 11, or 32 per cent are interchange stations.
Unquote:
Here is my analysis.
The number of stations increased by 30%. All the stations of the Downtown Line are underground.
Allowing for these two factors, I consider that the cost of the Downtown Line should be 2.5 times of the North South Line, i.e. $4.4 X 2.5 = $11 billion.
But we are paying $21 billion for the Downtown Line. It seemed that we are paying 2 times of what it should be, allowing for the points raised by the minister.
I fear that we are spending money on infrastructure quite recklessly. We are paying much more than we should be.
Tan Kin Lian