Are public transport trips longer (than car trips)?

Non-work trip distances (km) by car and public transport (%) - data from VISTA

I’ve frequently mentioned that trips by public transport in Melbourne are longer on average than those by car. The exhibit above illustrates that difference using data from the Department of Transport’s VISTA data base.

It shows the length of non-work trips in Melbourne by private vehicles versus public transport. For all practical purposes, it’s cars on the one hand (in red), versus trains, trams and buses combined on the other (in blue).

A ‘trip’ refers to travel between main activities. Where multiple modes are used on one trip a single ‘main mode’ is defined. For example, if a person drives from home to the station, catches a train to the city, and walks to their destination, their mode for the trip is the train.

It’s important to get these figures in perspective from the outset. There are almost fourteen times as many non-work trips made by car as are made by public transport. This reflects the dominance of private transport in Melbourne.

It’s evident from the exhibit non-workcar trips are substantially shorter – just compare the two fitted curves. In fact 56% are less than 5 km, whereas the corresponding figure for public transport is 27%. At the other end of the scale, 5% of non-work car trips are longer than 30 km, compared to 9% of public transport trips.

Work trips (i.e. commutes) tend to be longer than non-work trips in the case of both private and public transport, but again public transport trips are longer on average. For example, 40% of commutes by public transport exceed 20 km. The corresponding proportion for car commutes is much lower, at 27%.

I’ve shown non-work trips in the exhibit because they account for around four fifths of all trips (defined as per above). They are not as dominant in the case of public transport, but still comprise two thirds of all trips by trains, trams and buses.

Trains are the key reason public transport trips are so much longer – people travel considerably further on metropolitan trains on average than they do on buses and trams. I don’t have data to hand that separates out trains (I hope to get my hands on it shortly), but the difference between cars and trains would be much more dramatic.

It’s not that the train out-competes the car for long trips. In fact many more people still prefer to use the car for long trips than take any form of public transport. For example, while 7% of non-work car trips are over 25 km compared to 14% of public transport trips (they’re virtually all train), the car trips number 534,000 per day. The comparable number of trips made by public transport passengers is just 80,000.

Rather, people who choose to travel by train are more inclined to use it for longer distances, on average, than car travellers. I’d say that’s largely because Melbourne’s train system is designed to transport people across long distances – primarily from the suburbs to the city centre.

Cars are flexible and in non-congested conditions can get travellers to a range of dispersed destinations, both near and far. Melbourne’s train system on the other hand is relatively inflexible by comparison. It essentially leads to one destination.

That destination happens to be an extremely important location in terms of employment, leisure, cultural and social opportunities, so people are prepared to travel a long way to get to it. Because of congestion and high car parking costs, trains can often out-compete cars for this particular class of journey. Commuting is the obvious example.

It’s not unfair to characterise Melbourne’s CBD-focussed train system as a one-trick pony. It needs much more integration so it can provide access to many more destinations (think along the lines of the PTUA’s “Every 10 minutes to everywhere” campaign). The idea of a public transport network – a system – needs  to be promoted.

That’s why it’s disappointing to see Kenneth Davidson advocating a rail line down the centre of the Eastern Freeway to Doncaster in The Age on Monday. It might enhance the lives of Doncaster residents somewhat, but it wouldn’t do much to boost the strength of the network as a whole. In my view, system-enhancing expenditures like the Melbourne Metro (or if you prefer, other ways of achieving the same objective) should get priority.

6 Comments on “Are public transport trips longer (than car trips)?”

  1. Oz says:

    As always, an interesting analysis. We should be mindful that close to 30% of the MSD population are unwilling or unable to drive cars. For those without access to cars the length of the time budget available is the critical decision factor rather then distance.

  2. I’d also argue that the low-frequencies and difficult to remember timetables typical of most of the public transport network, especially outside of peak hour, makes cars that much more attractive. Its one thing to put up with waiting up to twenty minutes for a train if you’re planning on travelling for 40 minutes, but only a captive market will bother waiting 20 minutes for a bus to travel 10 minutes to the shops. Increasing frequencies on the rail networks could only really be achieved by hiring more drivers and keeping more of the peak hour fleet operational outside of peak times, however increasing frequencies of the bus network could be achieved with very little increase in overall costs.

    To achieve this a few fairly simple methods could be employed. Firstly, rationalising the bus routes so they are not frequently duplicating rail paths, or other bus routes would reduce the total number of routes needed freeing up buses to increase services elsewhere. Secondly modifying routes that meander slowly through suburban streets picking up and dropping off the odd lone passenger every few kilometres to instead stick to arterial roads would make routes faster, which would lower the number of buses needed to increase frequencies. Thirdly, dedicated road space and traffic light priority could be employed to again reduce the time it takes for buses to complete a full leg of a journey again reducing the number of buses required to achieve the same frequency. Dedicated road space and traffic light priority could also be deployed on the tram network, but it would unlikely have much bearing on the overall frequencies, it would however increase travel speeds and is worth doing for that reason anyhow.

    I would argue that the above methods should be employed before any major new infrastructure is built, they would cost only a tiny fraction of the Melbourne Metro tunnel, or the Doncaster rail line. I also believe getting the City Loop to run at something approaching its designed capacity is far more important than building another (very expensive) tunnel that will likely suffer the same fate as the City Loop. It takes only a cursory wander around Flinders Street station at peak hour to see that there is still plenty of rooms for efficiency gains.

    • T says:

      I agree that buses would be the easiest and cheapest way of improving the PT system overall and that should be give priority over a new rail line.

      Mainly, the bus system should be over-hauled so buses run along all major arterial roads (except those that already have a tram) to fill in the gaps in the system with some focus on connecting to train stations and shopping centers. Frequencies should be increased and all major roads should give up one lane as a dedicated bus lane during peak hour. Off-peak frequency should be no more than a bus every 10 minutes, making it a more viable and attractive option for non-work travel, and travel to destinations outside of the CBD.

      Surely all of that can be achieved for a lot less than it would cost to add a train line to Doncaster. Other cities do it and it’s very effective. People are only going to start increasing PT use during off-peak if services are improved, not the other way around.

  3. Car Carrier says:

    I agree with you “T” said really well.

  4. […] are much the same sorts of reasons why Melburnians drive for the great majority of work and non-work trips. They’re also the same reasons why all those readers of The Age who imagine they, or others, […]

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