In his speech, Transport Minister Khaw Boon Wan highlighted several differences between the 30-year-old North-South Line (NSL), Singapore's oldest MRT line, and its newest line, the Downtown Line (DTL).

He said that greater investment in better technology was fuelled by a growth in Singapore's per capita gross domestic product from $16,398 in 1987 to $73,167 last year.

The newer line is the more reliable of the two.

While the North-South Line achieved only 345,000 train-km between delays in the first half of this year, the Downtown Line hit 518,000 train-km between such delays.

COST OF BUILDING

• North-South Line: $4.41 billion (adjusted for inflation)

• Downtown Line: $21 billion

NUMBER OF STATIONS

• North-South Line: 26 stations, with eight interchange stations

• Downtown Line: 34 stations, with 11 interchange stations

NUMBER OF TRAINS

• North-South Line: 70 six-car trains

• Downtown Line: 88 three-car trains

PROPORTION OF UNDERGROUND STATIONS

• North-South Line: 40 per cent

• Downtown Line: 100 per cent

MAINTENANCE FACILITIES

• North-South Line: Shares the Bishan Depot with the East-West Line

• Downtown Line: Dedicated maintenance facility at Gali Batu Depot

AVERAGE NUMBER OF EXITS PER STATION

• North-South Line: Two

• Downtown Line: Four

SIGNALLING SYSTEM

• North-South Line: Originally analogue-based fixed block system, a new communications-based train control system (CBTC) is now being tested on the line

• Downtown Line: Has been running on digital-based CBTC since the start, which allows remote control of most train functions for greater reliability