Timetable Tuesday #145: Designed to fail? Frankston's high risk last bus connections

I was playing with the PTV journey planner the other day and noted this tight train - bus connection at Frankston station. It wasn't just any bus - it was the last of the night. Yep, the one that is both most necessary and easiest to get robustly reliable. 

As you can see it is anything but. The train arrives at 10pm. The bus leaves at 10:05pm. Four minutes is allowed for the walk to the bus stop. Hence if the train is just one minute late (well within what is considered 'on time') then the bus will be missed and there won't be one until the next morning. And note that we are not talking late night travel here; instead this is for a trip that starts before 9pm in the CBD (when it's still light in summer). 

Whether you sit in the first or the last carriage, or even which platform the train arrives at can have a bearing on your chances of making the bus. It's a dicey proposition that makes catching buses a gamble. Add the slightest train delay or personal mobility impairment and it's pretty much 'game over'. 

This counts for Frankston more than other stations. This is because it's a railhead with a very large catchment extending 30 or more kilometres. Hence the buses that radiate from it do more than the 'last mile' coverage normal for middle suburban stations. The result is that failure to make the bus makes walking not an option and results in a very steep taxi fare. 

These issues are exacerbated by Frankston's physical shoddiness as a transport interchange.

Buses do come tantalisingly close to trains. But try and walk between the two. 

What should be a direct walk is longer than it should be, not least because, despite its passenger volumes, interchange traffic and role as a suburban centre, Frankston station has but one entrance (at its south end). The recent station tart-up didn't really help. And some buses still stop too far from the station due to issues with Young Street. 

As you can see below, not having a middle and/or northern entrance increases walking distances and backtracking to some bus bays, including the one that the 781 leaves from.  

Ultimately Frankston station needs a proper rebuild. One that does useful things (like extra station entrances) and not useless things (like a roof with a hole in it or bus information displays placed so some passengers block others exiting). 

Unfortunately I can't see that happening soon. 

So the immediate question becomes how can we make the current interchange work the best it can? 

Part of the solution involves making sure bus timetables connect. Not just on paper but also in the 'real world', including if trains are slightly delayed. 

The Frankston line is fragile due to its 70km length from Werribee and interaction with other parts of the network (including single track portions near Altona). Trespassers, 'police requests', overhead faults, point failures and other incidents regularly delay trains. You can check how it underperforms the Metro network punctuality average here.     

As you saw from the journey plan above the 781's timings are anything but robust. A broken connection means (at best) an hourly wait or (at worst) the need to make arrangements to prevent being stuck at Frankston overnight.  This has happened despite the Department of Transport claiming to recoordinate the 781 and many other bus timetables with trains in early 2021.   

A systemic issue

Was having such a slim leeway for connections just a one-off accident with the 781's scheduling? Or does it demonstrate a bigger issue with bus connections at Frankston station? To find out I looked at the times the last buses leave Frankston and compared them with arriving train times.

I excluded routes that stopped running before 9pm (when trains are more frequent) and those that may have connections with other Frankston line stations. What remained was tabulated below. 

There is indeed train / bus connection planning at Frankston. That's unlike northern suburbs like Reservoir where weekday buses every 23 minutes have been missing 20 minutely trains for years despite lower train frequencies making connectivity planning more rather than less important.

Also (to the Department of Transport's credit) there are no ultra-tight <5 minute train - bus connections after 9pm at Frankston. But given that the journey planner allows 4 minutes to walk from train to bus, even a 5 minute connection is risky. The chance of failure is just too high with only a 1 minute leeway. Even just a few more minutes more can greatly reduce that risk.

There will always be some disruptions to trains and you cannot eliminate connection risk. But extending transfer time can usefully lessen it. It might even make the difference between experiencing a broken connection only a few times a year versus one or more nearly every week. They need to find a scheduling 'sweet spot' that gets the balance right. Whatever it is, it's pretty clear that the five minutes 781 allows isn't it.

For a large interchange like Frankston, where there can be significant walking times, I've assumed a 10 to 12 minute connection time as optimum. After deducting the assumed 4 minute walk time that drops to 6 to 8 minutes. If the bus is already at the stop and passengers can board early then waiting inside a stationary bus is better than waiting where there's no bus. Especially in winter. 

13 to 15 minutes gives even more robustness at the cost of journey time. The former is more highly valued for longer than shorter trips. Especially if we're talking about the last trip of the night. Also beneficial is the opportunity it gives for a toilet break at Frankston. The three longer distant routes (especially the 788) where this is more important are identified in the table. 

So much for the ideal, what's scheduled in practice? They couldn't be clearer. The 781's tight connection was the rule rather than the exception. Nearly 60% of after 9pm trips were equally tight, with just a 1 minute leeway. Only 4 out of 17 departures (ie less than 25%) had what I'd consider safe connection times at Frankston. And remember we're typically talking about the last trip where the time, money and convenience penalties for missing the bus are especially high.

The Department of Transport goes on about 'simple connected journeys'. However this analysis shows that, even when they recoordinate services, they are doing it to a specification that doesn't necessarily guarantee good results, whether measured by passenger success, travel speed or 'connection anxiety'.  

What is the fix?

There's basically two ways to improve 'last bus' connectivity. Neither involves more than minor costs. And since they typically involve the last trips in the busiest direction (ie outbound) there are fewer scheduling interactions than if you were attempting to reschedule trips earlier in the day. 

 I recommend: 

1. Longer train > bus connection times where needed. These should include reasonable access times and a better contingency for trains arriving late. What appears to be the current DoT rule of 5 minutes is too short for an interchange like Frankston. Instead of 5 to 10 minutes, maybe train to bus connection specifications could be 8 to 12 minutes. 10 to 12 minutes might be preferred for less frequent routes, longer routes or if it's the last trip. In some cases (for a nominally hourly evening service) it may be acceptable to have 65 minutes between the second last and last trips so that more contingency is built in for train connections to the last bus.  

2. A holding policy where the last bus is held if the train it is meant to connect to is delayed. This should apply on as many significant feeder routes as possible. Especially those that (a) meet trains at just one station and (b) do not form another trip in a popular direction. It should be publicised so passengers know which routes it will apply for and how long the bus will wait. An example already used at Frankston Station for Night Network routes could be extended to apply for the last trips of regular routes like those in the table above. 

Conclusion

Despite claims about bus services being recoordinated with trains, making a train > bus connection is chancier than it should be. Timetables allow insufficient time to change from train to bus, especially at larger interchanges. And there is almost no contingency for late running.

People don't trust the trains to be on time. Exacerbated by tight planned connections, train delays of mere seconds can cause a bus to be missed. The consequences in time, cost and potentially personal safety risk at night can present a barrier to using buses if coordination is poorly planned for and managed. While the Department of Transport spruiks its train-bus recoordinations, their widespread use of tight 5 minute connections risks making things worse not better for last trip connectivity. 

Two low-cost options, involving (i) more time at key interchanges and (ii) extending an existing  bus holding policy to apply earlier in the night would quickly improve end-to-end journey reliability and make multimode trips involving buses easier and more reliable. Longer term priorities could include reform of bus networks and redesigned train / bus interchanges to further improve connectivity.  

See other Timetable Tuesday items here