Saturday, October 23, 2010

New Frankston line timetable and bus connectivity

The major feature of the October 2010 Metro train timetable was the upgrade of the weekday Frankston interpeak frequency from fifteen to ten minutes. As frequencies increase dependence on timetables lessen. And many passengers would be treating ten minutes as a ‘turn up and go’ service.

Intersecting tram routes would also be considered ‘turn up and go’, at least on weekdays. However for buses reference to a timetable is still important to ensure short journey times.

Connectivity and effective service frequency are maximised if train and bus headways are harmonised. The extent of frequency harmonisation varies across Melbourne as each mode is often independently scheduled.

This survey shows the effect of the Frankston line train frequency boost on bus headway harmonisation for each bus route serving stations between Caulfield and Frankston.

Station – Route – pre Oct 2010 – post Oct 2010

Caulfield – 624 – yes – yes
Caulfield – 900 – yes – no

Ormond – 630 – no – yes
Ormond – 625 – yes - yes

McKinnon – 626 – yes – yes

Bentleigh – 701 – yes – yes
Bentleigh – 703 – no – no

Moorabbin – 811/812 – yes – yes
Moorabbin – 823 – yes - yes
Moorabbin – 824 – no – yes
Moorabbin – 825 – no – yes

Highett – 827/828 – no – yes
Highett – 708 – yes – yes

Cheltenham – 600/922/923 – yes – no
Cheltenham - 811/812 – yes - yes
Cheltenham – 822 – yes - yes
Cheltenham - 827/828 – no - yes

Mentone – 708 – yes - yes
Mentone – 811/812 – yes - yes
Mentone – 825 – no – yes
Mentone – 903 – yes - no

Parkdale – 708 – yes – yes

Mordialloc – 705 - n/a - n/a (peak service only)
Mordialloc – 708 – yes – yes
Mordialloc – 709 – yes – yes
Mordialloc – 903 – yes – no

Aspendale -

Edithvale – 858 – yes – yes
Edithvale – 902 – yes – no

Chelsea – 857 – yes – yes
Chelsea – 858 – yes – yes
Chelsea – 902 – yes – no

Bonbeach –

Carrum – 708 – yes – yes
Carrum – 780 – yes - yes
Carrum – 857 – yes – yes

Seaford – 780 – yes – yes

Kananook – 778 – yes – yes
Kananook – 779 – yes – yes
Kananook – 832 – yes – yes
Kananook – 901 – yes – no

Frankston – 770 – no – no
Frankston – 771 – no - yes
Frankston – 772 – yes - yes
Frankston – 773 – yes - yes
Frankston – 774 – yes - yes
Frankston – 775 – no - no
Frankston – 776 – no - no
Frankston – 779/780 – yes – yes
Frankston – 781/784/785 – no – yes
Frankston – 782/783 – yes – yes
Frankston – 788 – yes - no
Frankston – 789/790/791 – no - yes
Frankston – 832/833 – yes - yes
Frankston – 901 – yes – no

Total before: Yes 39 – No 13
Total after: Yes 39 – No 13

Notes: Routes with irregular headways (eg 703, 775, 776) are counted as non-harmonised. Only routes with off-peak weekday services are counted.

Analysis

While the move to a ten minute frequency has not changed the number of bus routes that can claim to be harmonised with Frankston line trains, to conclude that there has been no change oversimplifies the effect on individual routes.

The most significant harmonisation gain was that restored to 20 minute frequency bus routes. I say ‘restored’ because they were previously harmonised when Frankston interpeak trains ran every 20 minutes (before the 1990s upgrade to 15 minutes). Some of these routes (eg 630 and 824) were the busier services that escaped the bus service reductions in the 1980s and 1990s (which saw some weekday frequencies reduced from 20 to 30 minutes). The other harmonisation gain has been in the Frankston area, where routes to Karingal (789/790/791) and Mornington (781/784/785) now combine to provide an even connection to every second train.

The main loss to harmonisation has been to the SmartBus and near-SmartBus routes (600/922/923, 900, 901, 902 and 903). Their 15 minute frequency matched the previous interpeak train frequency on the Frankston line. The effective frequency (ie the interval between when optimum connections repeat) has increased from 15 to 30 minutes for trips involving a transfer. However many passengers are likely to treat this as a ‘turn up and go’ connection, especially if changing from the bus to the train.

Metro’s Andrew Lezala favours the introduction of ten minute interpeak train service frequency on more lines, along with similar frequencies on tram and major bus routes. The latter obviously involves the orbital SmartBus routes, which currently run every fifteen minutes.

This pattern provides a legible ‘one-size fits all’ pattern where almost every interpeak orbital service runs the full route, despite greatly varying patronage along it. However if bus patronage continues to rise and more train lines are upgraded to run every 10 minutes interpeak, a future change to a 10/20 minute frequency pattern (lower service on the quieter portions) could provide needed gains in capacity and connectivity. Efficiency would also rise as services more closely match demand. There would be some decline in legibility, as alternate services would terminate short, but this may be outweighed by the consistent connectivity achieved by matching bus and train frequencies and the higher service on the busier portions.

Conclusion

While the numbers show no change to the proportion of bus routes that are frequency harmonised with trains during the weekday interpeak, the higher train frequency has improved overally connectivity by reducing maximum waiting times. It is for this reason that the gain of a 20 minute headway service becoming harmonised is greater than a 15 minute frequency service losing it.

Nevertheless to enhance their potential as strong feeder services, the principle that SmartBus services should be headway-harmonised with trains is worth keeping, and an approach to enhance this for our orbital routes is suggested.

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