– Are cars the key challenge?

Share of journeys to work by car, 2006 (click). Map from Charting Transport

The accompanying map from Charting Transport shows the proportion of journeys to work in Melbourne’s inner city undertaken by car in 2006 — the rest were by public transport, walking and cycling (note that green denotes a low share for cars and red a high share*).

There is a clearly defined area — the ‘golden mile’, bounded by Spring, Flinders, Spencer and La Trobe — where cars capture less than 30% of all journeys. Around Swanston Street the share of journeys taken by car is as low as 24% (click to enlarge map).

But the really striking thing to my mind is the steep increase in car’s mode share as soon as you move beyond walking distance of the rail loop. You only have to go as far as the northern side of Victoria Parade and that share jumps to 50– 60%. Go toward the Hoddle Street end and it’s more than 70%. Once you get into the suburbs, most employment concentrations have a mode split that is 80% – 90% car.

One interpretation of the data is that sustainable modes are doing pretty well in the golden mile. Another is that they’re not doing well enough – maybe no more than 10% of journeys should be considered the ‘natural’ share of the car in this sort of key business area – and hence there’s an opportunity for public transport to increase its share.

I incline to the latter view, but I think there’s another interpretation of this data that’s arguably more significant. Consider what it takes, in terms of density and transit supply, to get the share of journeys to work by car down below 30%.

The ‘golden mile’ is just 2 km2 out of a built up area of around 2,500 km2 (the entire MSD is over 7,500 km2). That little area is the largest single concentration of jobs, by far, in the metropolitan area. It accounts for 10% of all metropolitan employment and is denser by an order of magnitude than any other activity centre in Melbourne, as exemplified by the number of very tall buildings it contains. And despite its diminutive size, it’s the focus of the entire metropolitan train and tram systems. It’s the ‘hub’ where all the ‘spokes’ meet – a giant transport interchange – and is accordingly, again by an order of magnitude, the most accessible place in Melbourne by public transport.

Yet for all the astonishing advantages of job density and public transport quality, a quarter to a third of all those who work in this tiny area still drive to work. Further, literally within one or two blocks of the rail loop, the car’s share of journeys to work rises to 50% and more, notwithstanding that these near-CBD areas themselves have a job density and level of public transport service that is far higher than the rest of the metropolitan area. And this is the journey to work – the trip most likely to be taken by public transport! Read the rest of this entry »


Is public transport ‘CBD dependent’?

Journey to work mode share, Sydney

A recent paper on travel in Sydney illustrates how dependent the CBD is on public transport and, in turn, how dependent public transport is on CBD commuting.

The paper analyses the journey to work in Sydney using data from the 2006 Census. It was undertaken by Blake Xu and Frank Milthorpe of the NSW Bureau of Transport Statistics.

Although the great majority of travel in Australia’s capitals is now undertaken for non-work purposes and is dominated by the car, the journey to work nevertheless remains an important travel purpose.
This is partly because it generates the largest peak in demand and partly because it is the one travel purpose where public transport’s mode share still remains relatively high.

The first chart shows that, as is the case with other capitals, public transport dominates commutes to the CBD in Sydney. It captures 75% of all journeys by Sydney CBD workers, whereas the car only gets 20%. That’s a bit higher than the other capitals but it’s an expected result.

Journey to work, market share by mode, Sydney

However what might surprise is that outside the CBD, public transport’s share is quite small. Only 13% of people who work elsewhere in metropolitan Sydney use public transport to get to work, while 80% drive.

When the CBD and the rest of the metropolitan area are taken together, the mode split for commuting for all of Sydney is 22% for public transport and 71% for car. Despite its high public transport share, the CBD has a small effect on the Sydney-wide average because it only has a small proportion of all jobs in Sydney – it accounts for just 14% of total work journeys.

Public transport patronage grew strongly in Sydney in absolute terms over 1981-06, but car use grew even faster. Transit’s share of work journeys fell from 25% to 22% over the period.

These numbers tell us that public transport is extremely important for the functioning of the CBD. Delivering large numbers of workers to the Sydney CBD in peak hour simply wouldn’t be possible without it. Read the rest of this entry »