Is medium density housing on tram routes sustainable?Posted: April 29, 2010
I like Melbourne City Council’s proposal for higher dwelling densities along tram lines but I think the claim that it would increase sustainability is exaggerated. There’s a whole ‘second half’ missing from this proposal.
The idea, which seems to be largely the brainchild of Council’s Rob Adams, is essentially that multi unit developments of up to 8 storeys should be encouraged along tram routes, leaving the suburban “hinterland” undeveloped (Rob refers to it as a new green wedge). This would reduce the need for fringe development and increase the mode share of public transport.
The major opportunities appear to be on tram routes in the inner suburbs, around 5-10 km from the CBD. While I think the assertion that 4-8 storey buildings can substitute for fringe development is fanciful and is based on a misinterpretation of other research, I accept that the proposal has the potential to increase the supply of dwellings of the type that are sought after by smaller households, especially those without dependents.
The key problem however is that nothing has been proposed to deal with car use by households occupying these new apartments. Without that, it won’t deliver. It just assumes that if households live cheek by jowl with good public transport they will necessarily use it.
I’ve previously pointed out (here) that this does not necessarily follow. A recent paper by David McCloskey, Bob Birrell and Rose Yip, Making public transport work in Melbourne, adds further support for this conclusion.
They point out that only 12% of all workers in Melbourne who live within 500 metres of a tram stop actually commute by tram. When they looked in detail at the stretch of Route 112 located north of the Merri Creek (between 5-10 km from the CBD), they found the share of workers who used the tram for work travel was just 13%.
The key reason most of these workers don’t use trams is because they are only really attractive for people who work in the city centre. For example, 43% of work trips to the City of Melbourne are made by public transport but for all other destinations the share is a mere 4%. So living close to public transport does not guarantee a high level of use.
That should not surprise anyone, given that the City of Melbourne, which is the only location in Melbourne where public transport is faster and cheaper than the car, has less than 20% of Melbourne’s jobs.
But the journey to work is not even the key issue – after all, it constitutes only around one fifth of all trips by Melburnites. So while residents of these new buildings might use the tram for 12% of work trips, they will barely use it at all for the great bulk of their trips.
The bottom line is that the great bulk of their travel will still be by car. Hence increasing density along tram routes will increase the number of car trips starting and ending on these roads. These are major roads so this will in turn increase traffic congestion. Perversely, the congestion will slow the speed of trams.
Residential intensification of tram corridors isn’t going to deliver the claimed sustainability benefits unless it comes packaged with a feasible plan to suppress car travel and provide high quality access by public transport to suburban jobs.
It is very unlikely that these new residents would locate on the fringe if these new apartments weren’t built. The kind of households who locate on the periphery tend to be families that want bigger houses and a yard. The likely market for inner suburban apartments along tram routes is primarily singles and couples without dependents. They will probably seek locations elsewhere in the inner suburbs.
Having said that, I like the idea of building apartments along tram corridors because it seems like another way to increase the supply of medium density housing in the inner suburbs. That would increase housing choice, albeit for a limited proportion of homebuyers, and help moderate prices in the inner suburban property market where demand is high.
It might also help to create more inner suburban precincts with ‘buzz’ and (hopefully) improve the visual appeal of the streetscape. There is also a risk some of the traditional character of key routes like Sydney Rd and High St might be sanitised. But what it is unlikely to do is improve sustainability significantly.