Thursday, October 14, 2010

Connectivity mapping and the interisland ferry

To date Melbourne on Transit has not covered ferries. This is because, unlike Sydney, Brisbane or Perth, they are not an established part of city public transport. And while proposals for commuter ferries are sometimes made, all trials of them have been unsuccessful.

This may be because Melbourne has an extensive rail network that largely follows the populated coast, serving areas such as Williamstown, Brighton, Frankston and Geelong that might otherwise support a ferry service. In addition the narrow Yarra does not divide the city like the much wider Sydney harbour, so land modes dominate travel to every suburb, with ferries strictly for tourists.

Outside Melbourne

However outside Melbourne there are two ferries that provide a service more direct than is possible by road. These are Portsea to Queenscliffe across the mouth of Port Phillip and the Interisland Ferry between Stony Point, French Island and Phillip Island. The operators of both these services are granted an exclusive licence to serve these routes by the Department of Transport.

The Interisland ferry serves three locations; the mainland outpost of Stony Point, the uninhabited nature reserve of French Island and the tourist and motor racing hub of Phillip Island.

The timetables are presented in tabular form on the Interisland website, with tables for each island. Only departure and travel times are shown, so arrivals must be estimated. Trips mostly operate beween Stony Point and Phillip Island via French Island, but sometimes the order is different, or services only serve two locations.

Transport operators normally provide a tabular timetable and separate map to help passengers plan their trips. This suits the whole range of service levels; from a weekly bus to an intensely served tram line.

However if only a few trips run per day and route variations exist, as is often true for country services, it’s sometimes more informative to combine the map and timetable on the one sheet. Each trip would have its own line between locations, like a train graph. And instead of being on a table the arrival and departure times would be written near the end of each line.

As well as being good for spacial thinkers, a graphical timetable tells much more about how the service works. The user can follow each vehicle around its run and identify relationships between trips, such as what forms what or how many vehicles are used, that are not disclosed on a table.

Below is a timetable-map made from departure lists on the Interisland ferry website.

I have arbitrarily seperated trips into six runs (not all daily) operating from Stony Point. These show how one ferry can run a variety of trips around the islands from morning until night.

The most common trip is between Stony Point and Phillip Island via French Island. However there is also a direct Stony Point – French Island return service and a trip from Stony Point direct to Phillip Island and then French Island.

Other transport

The only other public transport serving Stony Point is the train to Frankston. This is a country-style diesel service that connects with electric trains to Melbourne. Both the train and ferry have uneven intervals between trips; in the train’s case due to a single track, and for the ferry because the operating pattern includes several trip variations.

The ferry runs a basic 7-day timetable, with extra or deleted services depending on the day of the week. In contrast, like most land transport routes, the train has different times for weekdays, Saturdays and Sundays.

As well as the ferry, Phillip Island (whose east is joined to the mainland by road) has a coach service operating to several locations including Melbourne CBD. Although longer as the crow flies, this involves fewer changes than the two trains and ferry route via Frankston and Stony Point.

Showing connectivity

A full multimodal timetable-map for the area would have at least three versions – one for each day pattern. This would show connectivity in a more graphical form and make analysis of it easier. Each train and ferry trip could be shown graphically, with waiting times given for each connection.

The map above takes some short-cuts including showing all days on the one map and listing rather than drawing train arrivals and departures. Connectivity from Melbourne CBD is also not shown; potentially an issue on Sunday mornings where the service that feeds the first train to Stony Point is not a Metro train but a NightRider Bus.

Nevertheless having all times on the one sheet allows easier comparisons of connections. And by being able to see where a train or ferry is at a particular time, including dwell times, a graphical format should make it possible to check if any proposed time changes would increase or lessen connectivity.

Limitations

Even the best timetable presentation method may not necessarily correspond with how services are actually run. An example is the habit of some schedulers to round travel times down in the early part of the trip but add the minutes back between the second last and last timepoints. The benefit here is that though the service may appear a couple of minutes late when passing some timepoints, it arrives at the destination on time. This may lessen early running and waiting at timepoints. Early running, in particular, is objectionable, and performance standards treat it more harshly than minor late running.

In the case of the ferry, the first Sunday train arriving at Stony Point (arriving 8:01am) would appear to just miss the ferry (timetabled departure 8:00am). However my understanding (gathered when researching this piece) is that although pasengers are asked to be at Stony Point well before the departure time, in practice the ferry will wait for the train, making an apparently impossible connection work.

1 comment:

Anonymous said...

Hi Peter

I was looking for some Melbourne Metro blogs and found your site. Is there any chance of you changing that background, as it makes the text difficult to focus on.

Cheers

Marc