Is Melbourne’s promised loop rail line justified by jobs growth in suburban centres?

Second, just three of the major suburban job clusters identified by Mr Loader are on the route of the promised loop i.e. Clayton, Box Hill and Heidelberg. They're the biggest major centres, but collectively they still only account for around 4% of metro jobs.

Centres mostly minnows

Third, most of the other 12 centres on the loop are relative minnows in terms of job numbers. My own analysis shows that while the cluster comprising the airport and surrounding industrial area accounts for 1.5% of metropolitan jobs, all the other centres each have fewer than 1% of jobs (see Where are the suburban jobs?).

For example, Doncaster has 0.1% of metropolitan jobs and Sunshine, Broadmeadows, Burwood and La Trobe each have 0.2%. Although I use very low thresholds for total jobs and employment density (much lower than those used by Mr Loader), three of the centres on the loop – Cheltenham, Fawkner and Werribee – don't qualify.

Density of centres is modest

Fourth, the 15 centres on the suburban loop are all a far cry from the CBD, which accounts for most commuting by train in Melbourne. The expanded CBD, including Docklands and Southbank, is four times denser than Box Hill and seven times denser than Clayton. The Hoddle Grid is nine times denser than Box Hill and twelve times denser than Clayton.

Centres have big footprint

Fifth, a number of the 15 centres are geographically expansive, making them less suitable for high-capacity transit systems. The draft planning framework for the Clayton NEIC covers an area of circa 16 sq. km. Even the Sunshine NEIC, although tiny in terms of jobs, extends over approx. 15 sq. km. Similarly, La Trobe NEIC is about 13 sq. km. In contrast, the CBD rail loop encloses an area of 2 sq. km. and services it with 5 stations.

Most centres already on rail

Sixth, 13 of the 15 centres on the promised suburban loop are already on radial rail lines. Yet these 13 haven't grown into massive job hubs. In fact, the largest suburban cluster, Clayton, has developed despite very poor rail access. This suggests that even radial lines connected directly to the massive job concentration in the city centre aren't a silver bullet for growth or density in suburban centres; there are other factors that matter more. It also implies an orbital rail line that mostly connects minnows with each other is unlikely of itself to be a catalyst for significant jobs growth.

Major centres not increasing share

Seventh, the argument that the suburban centres will grow dramatically in the future isn't convincing. Melbourne got much larger over the last 50 years and for much of that period jobs grew faster in the suburbs than in the inner city. Yet the proportion of suburban jobs in centres declined for most of the period. That's in line with the experience in American cities too.