Well-planned skip-stop rail scheme could be successful

Several cities, including New York, Philadelphia and Helsinki, have commuter rail lines with single-track segments where skip-stop train services have been implemented successfully.

A skip-stop rail scheme involves trains stopping at some stations and bypassing others on a line.

Thus, an analysis of these lines is relevant to Singapore’s current single-track MRT system and skip-stop services can be explored even on lines that do not allow for overtaking.

It has been remarked previously that a skip-stop scheme with our current MRT system during peak hours could cause about 40 to 50 per cent of commuters to change trains to reach their stops.

With thoughtful design, though, some variant of a peak-hour skip-stop scheme, involving only some stations, could be implemented successfully.

The first variant could be an A/B scheme for selected stations, designated as A or B stops; all other high-traffic stops should be designated as AB stops for both A and B trains.

The A and B stops could be alternating and consecutive to prevent excessive disruption to scheduling and signalling. Possible candidates include Kembangan/Eunos and Commonwealth/Queenstown on the East West Line, Kranji/Yew Tee on the North South Line and Farrer Road/Holland Village on the Circle Line. In a more aggressive scheme, higher-traffic pairs such as Simei/Tanah Merah, Lakeside/Chinese Garden, Newton/Novena, Little India/Farrer Park and Buangkok/Kovan could be considered.

As long as we ensure that popular destinations are AB stops, we can keep to a minimum the proportion of commuters who have to change trains.

In another variant, on lines with heavy flow in both directions, trains could skip stops with less traffic in the peak direction and serve all stops in the non-peak direction. With peak flows in both directions on different segments of the line, headway can be balanced by balancing the number of stops to be skipped in both directions.

Also, the additional waiting time incurred by stop-skipping must be offset by more frequent trains and a sufficient number of skipped stops, taking into consideration the asymmetrical distribution of passengers between high-traffic and low-traffic stops.

Through careful planning and sufficient effort from the authorities, we can use this established method of transit to enhance our public transport.