Our first ten minute line

Sunday marked the start of a new timetable for several Melbourne suburban rail lines. The revised timetables feature increased weekday peak services on some busy lines and six car rather than three car trains on others to lessen crowding.

However the most important change in terms of how passengers will view and use the train network is the new Frankston line off-peak weekday timetable. This sees train frequencies increased from every 15 minutes to every 10 minutes. And weeknight 7 - 10pm headways are down from 30 to 20 minutes, reversing most of the 1978 evening service cuts.

Even though government transport plans normally stress infrastructure over service levels, there is no question that the October 10 timetable is significant for several reasons:

Firstly it makes Frankston the first railway line to operate at a tram-style 'turn up and go' frequency (Werribee's 6 trains/hour doesn't really count due to its uneven headway). In doing so it challenges an oddity where trams run more frequently than trains, despite rail's larger catchment area, coverage of major suburban centres and greater importance of connectivity with buses.

This upgrade provides a service at least every ten minutes for the 26 stations from Frankston to Richmond. Beyond Richmond the service frays into two patterns - one via the City Loop and the other direct to Flinders Street. Like the current Werribee operating pattern, these alternating services reduce legibility and effective frequency in the CBD, so are hopefully an interim transitory step before a single operating pattern can be introduced.

Secondly, while not marketed as such, it is understood that these trains form a direct Werribee service, allowing a one-seat ride from Frankston to stations such as Footscray, Newport and Laverton. Through-routing like this was typical before the Loop commenced, so this change represents an element of 'back to the future'. Linking the Werribee and Frankston lines could improve travel speeds for cross-city trips, but care will need to be taken to avoid Werribee's reliability being dragged down by Frankston line problems (and vice versa).

Thirdly is the decision to choose the Frankston line. If you were choosing which lines deserved a higher off-peak service on the basis of likely patronage increase, the Frankston line would be unlikely to figure. Instead the lines to Ringwood, Dandenong and probably Sydenham might have a greater call. These lines have all have large middle suburban trip generators, including universities, that generate off-peak and counter-peak travel. The very high concentrations of low income earners around Sunshine - St Albans and Noble Park - Dandenong (Sydenham and Dandenong lines) also tend to generate high off-peak demand outside commuting hours.

Nevertheless the Frankston line off-peak is not what you'd call a quiet line like Williamstown, Alamein or Sandringham. It has operational advantages such as the ability to run through to Werribee. And as an experiment certain changes (eg to loop running patterns) might not be as controversial as one conducted on a busier line.

Fourthly, the change is reversing a significant decline in overall Frankston line service, both in absolute and relative terms.

The absolute decline has been in reliability. While this has occurred across the network, factors such as Siemens trains (and their speed restrictions), the number of level crossings (and consequent disruptions) and it being part of the busy Caulfield group, the Frankston line is particularly prone to delays. In rough figures, Frankston passengers experience twice as many late trains than the Melbourne average, and nearly three times as that on reliable lines such as Glen Waverley.

The relative decline can be measured against the Cranbourne and Pakenham lines, Frankston's sister lines on the Caulfield group. In the 2004 - 2009 period Frankston tended to miss out on additional services. Those that were added went to the busier and faster-growing Pakenham and Cranbourne lines instead.

June 2010 saw renewed interest in the Frankston line, with a new timetable adding peak services. While there remain timetable 'holes' of 15 minutes or more, most Frankston line stations got at least a 10 minute service, with busier stations at a five minute peak frequency approximately. The trade-off was that most of its express trains ran direct to Flinders Street instead of via the loop - speeding some but slowing others.

This interest is continuing, with this week's 50% off-peak frequency increase for all Frankston line suburban stations. The significance of this can be measured by reviewing previous service changes of similar magnitude. The last would have been back in the 1990s, where off-peak weekday services on some south-eastern suburban lines went from 20 to 15 minutes. Subsequent increases tended to favour Sundays, late evenings, peak periods or parts of lines only, leaving basic Monday - Saturday off-peak and evening service levels intact up to now.

Conclusion

The Frankston line presents both challenges and opportunities for Metro.

Challenges because its low on-time performance consistently drags down the metropolitan average, and thus the ability to meet targets.

And opportunities since the October 10 Frankston timetable is the first test of Metro's vision for a frequent-service metropolitan railway.