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Activity centres

Apr 19, 2013


Texas - where even the hospitals come in super-sized servings. Texas Medical Centre, Houston

This is an image of the Texas Medical Center, a staggeringly large stand-alone suburban medical complex in Houston. I haven’t been to Houston and wasn’t aware of this amazing ‘city within a city’ until someone I follow mentioned it on Twitter this week (More images here).

According to Wiki it contains: 50 medicine-related institutions, including 15 hospitals and two specialty institutions, three medical schools, four nursing schools, as well as schools of dentistry, public health, pharmacy, and other health-related practices. It’s next door to Rice University.

It gets 160,000 visitors per day, performs more heart surgery than any other centre in the world and employs 93,500 workers. As a point of comparison, Sydney’s Barangaroo is expected to accommodate 15,000 jobs when built out.

It looks like a compelling example of the benefits organisations see in agglomeration. Workers can change jobs without changing carparks, employers can find skilled workers relatively easily, there’s an immense array of basic and highly specialised medical services within the same 1,000 acres, and the scope for face-to-face contact, joint projects and serendipitous meetings must be enormous.

It also seems to demonstrate the benefits of specialisation. Rather than bear the cost of high rents and congestion in a CBD location where unrelated sectors compete for the same space, the Texas Medical Center is a constellation of organisations in closely-related industries.

The social and economic benefits of complete strangers sharing the same streets, corridors and cafes is often over-stated, but in a place like this arguing the benefits of chance encounters and knowledge spillovers makes more sense.

There’s a greater liklihood workers will run into someone they’ve met previously or with whom they at least have the basis for an introduction. They’ll be people in the same industry and so more likely to have a shared interest and the potential for economically productive exchanges. (fn 1)

One of the basic urban questions is whether there’s a bigger economic pay-off from diversity of activities or from specialisation. This is an example of the latter (and is consistent with the increasing specialisation of activity centres in Australian cities).

The second exhibit is from Google Maps (click to look around in Streetview). This is doubtless a heavily car-based suburban centre, so it’s interesting to see there’s a light rail route through the complex that also connects it to downtown Houston.

Houston seems to have a thing for institutional concentration. The Texas Medical Center is next door to the Houston Museum District, which has 19 museums within a radius of 1.5 km.


(Fn 1) Density promotes social interaction too. I’d like to see an enterprising researcher compare the level of social connection among health workers (e.g marriages) at a place like this compared with other health establishments.
Texas Medical Centre in Google Maps - click to take a virtual tour in Streetview



Dec 3, 2012


Where workers employed at Monash-Clayton live

The Baillieu Government’s newly released discussion paper on Melbourne’s Metropolitan Strategy is nominally intended to generate ideas and promote open discussion about future possibilities for the long-term planning of the city.

However a couple of matters are apparently so important for the city’s future that the authors thoughtfully made up residents’ minds for them. One of those is a commitment to making Melbourne a “20 minute city”.

Whether they like it or not, the authors decided apriori that residents should be “living locally”. All Melburnians, it says,

should have access to the services and facilities they need within a 20 minute journey from home.

I’m disappointed the paper effectively pre-empts debate on this issue by making the 20 minute city one of the discussion paper’s nine foundation principles. Nevertheless it sounds like a principle all reasonable persons could agree on, doesn’t it?

After all, the evolution of transport technology – from walking to beasts of burden to rails to cars to planes – shows humans seek to minimise time spent getting to and from places.

The paper pulls its punches though when it comes to mode. It’s not saying all of Melbourne should be a 20 minute walking city, or a 20 minute cycling city, or even a 20 minute public transport city.

While it acknowledges the inner city probably already offers 20 minute accessibility on foot, it’s happy for the 20 minute limit to include driving time. That’ll trouble some observers but I think it’s realistic.

Since more than 90% of the population live in the suburbs, that’s a reasonable definition. It would be jejune to set a 20 minute walk as an objective when 89% of households have access to at least one car.

Residents aren’t going to go back to walking to a small local hardware store when they can drive to Bunnings within 20 minutes and get significantly lower prices, a vastly bigger range to choose from, and easy parking.

Unless there’s an extraordinarily large increase in the marginal cost of driving, as well as some constraint on the scope to adapt (e.g. to more efficient vehicles), consumers will want the benefits that economies of scale and scope provide.

This is where strategic planners should look beyond conventional infrastructure and land use policies and actively canvass non-physical ways (e.g regulatory and taxation initiatives) to promote use of more efficient cars.

But even if the aspiration of a largely car-based 20 minute city is accepted, I don’t think the case has been made that “living locally” warrants being one of the Strategy’s foundation principles.

Paradoxically, we’ve already got it and it’s unachievable.

We’ve already got it because there are very few places in Melbourne, even in the outer suburbs, where you can’t already get to a supermarket, hairdresser or GP within a 20 minute drive. By this standard, Melburnians are living the local dream already.

On the other hand, it’s unachievable because there are some higher-level activities that simply can’t be distributed evenly across the entire metropolitan area so that they’re within a short walk, bus ride or drive of almost every household.

For example, there are major sporting facilities, universities, private schools, night club strips and fashionable restaurants, that either locate in clusters or can’t be disaggregated. Cities are “lumpy” and “spiky” places.

The journey-to-work is the best example because it’s a frequent trip. Some jobs are indeed local, but it’s a fallacy they’re filled completely by locals.

Workers are prepared to travel considerably longer than 20 minutes to find a better job. The median journey-to-work time in Melbourne (all modes) is 30 minutes and the world’s biggest, densest cities are in the same ball park.

Many jobs also agglomerate due to internal and external economies of scale. Suburban universities, hospitals and heavy manufacturing are examples of industries that have regional and metro-wide catchments.

The pre-eminent example is the CBD and surrounds, which attract workers from all across the metropolitan area. Because it’s dependent on public transport, journey-to-work times are considerably longer on average than they are for (overwhelmingly car-based) suburban jobs.

Workers can of course choose to live close to their jobs and many years ago when transport costs were very high that’s what they mostly did. But these days housing within 20 minutes of the CBD is extremely expensive, especially for larger households.

Once most households only had one full-time worker so location decisions were relatively straightforward. Today’s households however are likely to have multiple workers. Some have members who attend non-local universities and schools (around a third of all high school enrolments are at private institutions).

The idea of a 20 minute city is also at odds with increasing use of public transport. It’s not like a car – walking, waiting and transfer time might be minimised but they can’t be eliminated.

At present the median work journey by public transport in Melbourne takes 55 minutes, compared to 30 minutes for workers who drive. That’s partly walk and wait time but trains in particular enable many residents to trade-off travel time for more living space.

Even in a city as dense and well-serviced by transit as Manhattan, it’s not easy for anyone other than the very wealthy to live within 20 minutes total travel time of work.

You can certainly “live locally” if you’re in a small regional city or country town. It also makes sense to improve the quality of life in neighbourhoods since we spend a lot of our lives locally (although not necessarily in the same neighbourhood – we usually shift frequently).

There’s potentially a lot to gain from encouraging a sense of community and identity within urban neighbourhoods. But it’s too restrictive – and unrealistic – to expect residents would want to, or could, do most everything locally, or that all businesses and services fit the distributed model.

The implicit idea that a key mission of planning in a city of four, five or six million people is to promote “living locally” as the headline objective is to misunderstand what a city is about.

Cities offer specialisation and that means higher level activities aren’t evenly spread in the way that hairdressers and supermarkets are, but tend to be geographically concentrated. Having access to those specialisations is one of the advantages of living in a city and ought to be facilitated.

At the least, there are legitimate issues here than ought to be part of the debate around the metropolitan strategy, not assumed to be right from (before) the get-go. That’s not what consultation and participation should be about.

Activity centres

May 5, 2010


The Premier wants a Melbourne which encourages the transformation from a mono-centric to a multi-centred city, “so that people can work closer to where they live”. He goes on to laud Melbourne as “a city we’re all proud of – ‘a city of villages’, a whole that is greater than the sum of its parts.”

I’m not completely sure what he intends but I wonder if he’s thinking about “urban villages” where the great bulk of jobs are filled by local residents who live at density and walk to work. This is an old idea in planning and the Victorian planning department ran strongly with the idea in 1996.

Kogarah Town Centre

Whether or not “employment self-sufficiency” can be achieved in practice depends on the level of geography. If we look at Melbourne from a regional perspective, most people already work in the same region in which they live (other than for jobs in the CBD)  – see this paper by Kevin O’Connor and Ernest Healy. The median journey to work time in Melbourne is consequently a reasonable 30 minutes by car (55 minutes by public transport, reflecting longer trips to the city centre).

However achieving something like “self-sufficiency” in employment at a smaller geographic level is hard. There are a number of reasons for this.

One is the increasing complexity of households. In two income households both parties frequently work in separate locations, so they either elect to live near one member’s workplace (and if so which one?) or they select a compromise location. Children who continue to live at home after they’ve entered the work force have no flexibility to live closer to where they work. If changing jobs involves a change in job location then that adds another layer of difficulty.

Another reason is that the journey to work has declined in importance as a determinant of where people live. It now accounts for only one fifth to one quarter of all trips, as people travel a lot more for other purposes than they used to. There is now less reason to live near work. Other factors like the level of local amenity seem to be an increasingly important determinant of the residential location decision. Continue reading “Are "urban villages" living in the past?”