I’ve said before that there isn’t one ‘Melbourne’ – there are multiple ‘Melbournes’. The home range of Melburnians is pretty restricted – the great bulk of their travel is made within a region defined by their home municipality and contiguous municipalities. Many suburbanites rarely visit the city centre, much less the other side of town.
This pattern of sub-regionalisation is illustrated by Melbourne’s three major universities. I posted on March 16th about the mode shares of work trips to these universities. To summarise, at the time of the 2006 Census, 41% of Melbourne University staff drove to work while over 80% of staff at Monash and La Trobe Universities commuted by car.
The accompanying charts look at something else – where university workers lived in 2006. They show a number of interesting things.
The first chart indicates that staff of these three universities don’t tend to live west of the Maribyrnong. The west has 17% of Melbourne’s population but houses only 8% of Melbourne University’s staff. The ring road provides good accessibility from La Trobe to the west but even so, only 3% of the university’s staff live there.
Second, Monash and La Trobe serve distinct regional markets, in the north and south (of the Yarra) respectively. Melbourne University has a more metropolitan ambit but it still has a sub-regional focus – its staff strongly favour the inner city and the inner northern suburbs.
Third, university staff like to live close to their employer. This is particularly evident with La Trobe, where 56% of staff reside within the four municipalities closest to the university i.e. Darebin, Banyule, Nillumbik and Whittlesea (see second chart). Read the rest of this entry »
Yesterday I talked about what I thought the new Metropolitan Strategy for Melbourne should be. That was mostly ‘mothers milk’, so now I want to say something about the substance of the strategy – what it should do. I have (mostly) refrained from proposing specific policies or solutions, preferring instead to point out the key policy challenges or directions.
Among other things (this is not exhaustive) the new Metropolitan Strategy should:
Recognise that 90% of motorised travel in Melbourne is made by car and that there are myriad ways drivers and manufacturers are adapting to higher fuel prices. The great majority of travellers prefer to drive if they can despite the expense – they’re not going to give up driving for public transport unless they’re made to.
There are three key challenges in relation to cars. First, provide incentives to increase the speed of the transition to more fuel and emissions efficient vehicles. Second, make cars more civilised – make them slower and quieter and remove their priority over other carriageway users. Three, manage congestion so that gridlock is avoided and high value trips are given priority.
Recognise that public transport is only a substitute for cars in a limited number of situations. It has two key but growing roles. One is to transport large numbers of people to and from places with high trip densities, like the CBD, where the car is simply incapable of carrying so many people. The other is to provide mobility for those without access to a car.
The focus of public transport policy should be on these two roles. They mean a different approach to public transport from that implied by the popular idea that public transport must always be provided at a level which provides a “viable alternative” to car travel. Read the rest of this entry »
I’ve previously pointed out some of the areas where I think Melbourne 2030 was found wanting, so I’ll offer some thoughts on what the new strategy should be and do, starting today with what it should be.
First, it should be a strategy for managing the growth of Melbourne. It can’t just be a land use plan, limited to the Planning Minister’s domain. It has to take a multi-portfolio view because planning is only one force shaping the way Melbourne will develop over the next 20, 30 or 40 years. In particular, it must recognise the intimate long-term, two-way relationship between land use and transport, both public and private.
Second, it should positively embrace so-called ‘soft’ policies like regulation, taxation and marketing. It must not limit its perspective solely to ‘hard’ initiatives like capital works and zoning regimes. These are important because they’re long term decisions, but how Melbourne develops in the future will be shaped as much by how behaviour is managed as by what projects are constructed. There are, for example, a host of regulatory and taxation policies – e.g. road pricing – that can potentially have a profound impact on shaping the way the city develops (and not all of them are as politically fraught as road pricing). Some can obviate the need for capital works.
Third, it should focus single-mindedly on what can be done most efficiently and effectively through a growth management strategy. It should resist the temptation to ‘solve’ every economic, social and environmental issue confronting Melbourne. Sometimes what are seen as urban issues are more the symptom of other processes rather than the underlying cause – I’ve previously suggested that diversity is one such issue. It’s important that the strategy understands how it impacts on, or even exacerbates, variables like diversity, but close attention should be given to whether or not it is the appropriate vehicle to achieve change. Read the rest of this entry »
The nearest point of Albert Park is 9 km as the crow flies from my house yet today I can hear it inside. It’s not loud enough to be annoying – just part of the background hum really – but I’m astounded that I hear it at all.
That makes me wonder why F1 has to be so extremely, incredibly loud. According to the cost benefit analysis published by the Victorian Auditor General on the 2005 race, the estimated peak noise level trackside reaches 125 dB(A) and 105 dB(A) at 100 metres. The report says above 70 db (A) is annoying and 115 dB (A) can cause hearing damage, although this depends on the duration and the vulnerability of the listener.
I’ve only visited Albert Park once but that was enough – I found the noise excruciating. Ditto the Gold Coast Indycar. Even with foam ear pads plus a set of those external headphone-type sound dampeners it was still plenty loud enough. At some events the organisers also send an air force jet over at low altitude, presumably to show what real noise is!
The Auditor General reckons the impact of noise from the 2005 event ‘cost’ 12,500 neighbouring households a combined $415,000 (not that they were actually compensated!). Households within the 70 dB (A) contour suffered an estimated disamenity of $50 per week and those within the 80 dB (A) contour – where the noise level is generally regarded as intolerable – suffered $100 per week.
I’d debate the methodology but there’s some relief coming in the 2013 season when a new ‘green’ four cylinder turbo charged engine has been mandated by the Federation Internationale de l’Automobile (FIA). It will be significantly quieter than the current eight cylinder engine but it seems noise is in the DNA of the sport. F1 boss Bernie Eccelstone is at loggerheads with the FIA over the change. This week he said:
I meet people worldwide in all different walks of life – sponsors, promoters and journalists – and I think there are two things that are really important for Formula One. One is Ferrari, and second is the noise. People get excited about the noise. People who have never been to a Formula One race, when they leave you ask them what they liked, and they say ‘the noise.’ It’s incredible, it really gets to you.
With serious questions being raised about the viability of the Grand Prix in Melbourne, it’s time for Bernie to embrace this change. The Auditor General found that the costs of the event exceed the economic benefits, let alone the cash outlay. Reducing the impact on residents affected by the noise footprint might help fans retain the race. In fact the sport should go further to embrace ‘green’ thinking as I argued this time last year.
This is a recently released animation of 24 hours of traffic in Los Angeles. It’s constructed from reports sent from the smartphones of Waze users. Waze is a “social mobile application providing free turn-by-turn navigation based on the live conditions on the road and driven by users”.
It starts at 4pm but really goes beserk the next day in the AM peak. As far as I can work out, red dots are concentrations of high congestion and green dots are hazards reported by Waze users.
Herald Sun journalist Andrew Bolt glosses easily over the potential negative health implications of the troubled Fukushima Dai-Ichi nuclear reactor in Japan. He says too much emphasis is given to the Chernobyl disaster because, contrary to received wisdom, he maintains only 65 deaths are associated with this accident. But there’s more to it than that.
These accounts (here and here) from Wiki indicate there are wildly varying claims about the number of deaths associated with the accident. The World Health Organisation estimated deaths at 4,000; Greenpeace at 200,000; and this Russian report, translated in 2007, says there were one million deaths, 170,000 of them in North America.
However estimates of deaths by the UN Scientific Committee on the Effects of Radiation are broadly consistent with Andrew Bolt’s claims. But what Bolt fails to mention, and the UN draws attention to, is the long run health implications of the accident.
For example, by 2005 there were 6,000 diagnosed cases of thyroid cancer among residents of Belarus, Ukraine and proximate parts of Russia, who were children at the time of the accident. According to the UN, it is most likely that a large fraction of these cancer cases are attributable to radioiodine intake (fortunately, thyroid cancer is usually treatable – the 30 year survival rate is 92% – but it’s a gruelling experience).
Now a new study has drawn attention to the cognitive risks of radiation exposure. Douglas Almond, a Columbia University Professor, wrote to the New York Times earlier this month pointing out that even low levels of radiation can have severe consequences for unborn children. He and his collaborators recently published a study of the effect of fallout from Chernobyl on Swedish children.
Sweden experienced radiation levels from Chernobyl that were so low they were considered safe. Almond’s team confirms that this presumption was mostly right. However they found that “Swedish students who were in utero during the accident experienced significantly lower cognitive functions, as reflected in performance on standardised tests in middle school, especially those tests that correspond best to IQ”. Read the rest of this entry »
I regularly hear the argument that there’s no point in Australia putting a price on carbon because we’re so small it will mean jack shit at an international level. We’ll suffer the pain, so the argument goes, for no gain.
Australia is one of the world’s highest emitters of greenhouse gases on a per capita basis, but because we’re small, we only account for around 1.8% of world emissions. By 2020, our emissions are supposed to be 5% below what they were in 2000 – if we were to achieve that target it would, in quantitative terms, amount to an extremely small reduction in total world emissions (although on current policy settings we’ll actually be 24% over the target!).
It’s commonly argued that we should therefore hold off until the big emitters like the US and China take parallel action.
There are a number of reasons for not accepting the “we can’t act alone” argument. Some argue that action now will give us an early start on sustainable industries; some that a carbon price could foster a culture that is more receptive to the wider idea of sustainability; and some that a carbon price is a more efficient way of addressing climate change than direct expenditure.
But there are two arguments for rejecting the “we shouldn’t go it alone” thesis that particularly resonate with me.
The first one is an unashamedly moral argument – I think we should clean up after ourselves as a simple principle of ethical responsibility. If we despoil the quality of the world’s environment we should fix up the damage we create, independent of what other nations do. We should do the right thing.
The second reason is more instrumental. It’s in our interests to encourage the big emitters to take action because we all suffer from the build up of greenhouse gas. They’re hurting us so we should be prepared to accept some pain to try and make them change their ways. It’s worth it for us to show, by example, what needs to be done, how it can be done, and that some nations think it’s worth doing. In other words we’re not so much “going it alone” as “setting a good example”.
P.S. Here’s another version of the Time history of CO2 – it’s clearer, but no music.
I have a heightened consciousness about diesel buses and 4WDs belching carcinogens because I’ve just finished reading Siddhartha Mukherjee’s excellent book, The Emperor of all Maladies: a Biography of Cancer.
Melbourne’s fleet of 1700 buses is powered almost entirely by diesel engines. Each year they collectively travel around 80 million kilometres, each bus consuming 90 litres of diesel per 100 km. That’s more than 70 million litres p.a. in aggregate.
Melbourne’s taxi fleet, on the other hand, is comprised mainly of LPG powered vehicles. LPG offers a small saving in CO2 emissions compared to diesel (about 10%) but its main advantage is much lower pollution. Compared to ultra-low sulphur diesel, LPG produces less than a fifth as many particles and less than 1% as many ultra-fine particles. It also produces less than one tenth as much oxides of nitrogen (NOx).
One company estimates the cost of converting the engines in the existing bus fleet to LPG at around $55,000 per vehicle. The company says buses that use LPG consume about 100L/100km (about 10% more than diesel buses) but there’s a significant saving in the cost of fuel.
The price of LPG is currently less than half the price of diesel. A bus that covers (say) 100,000 km p.a. would cost $130,500 p.a. in diesel (at today’s price of $1.45 per litre) but only $60,000 p.a. in LPG (at $0.60 per litre). That means the cost of conversion could be recouped within a very short period. This difference depends on factors like distance driven and fluctuations in relative prices. For example, a new excise on LPG of 2.5c a litre comes into effect from July this year, rising to 12.5c over the next four years. On the other hand, the current troubles in the Middle East have increased oil prices.
This highlights another singular advantage of LPG over diesel – it’s less dependent on international price fluctuations. Australia has immense reserves of natural gas from which the propane and butane in LPG are derived. Proponents of LPG also argue that it extends engine life, reduces maintenance and makes buses less noisy.
There appear to be many good reasons for bus operators to shift to LPG so why hasn’t this happened? Read the rest of this entry »
The key transport challenge at Melbourne Airport isn’t to build a rail line to the CBD. Rather, it’s how to move growing numbers of travellers from dispersed suburban locations to the airport and back again. Here’s a (speculative) idea about how that might be done.
This is a pressing issue because passenger movements through the airport are projected to increase from 26 million in 2009/10 to between 44 and 55 million by 2027/28. That’s potentially a doubling of demand within twenty years. On current settings, with 69% of trips to the airport made by private car and 17% by taxi, the outcome could either be gridlock or massive expansion of the freeway network.
Providing a high capacity connection between the airport and CBD is an important part of the answer but it won’t work for all those travellers whose journey starts or ends in homes and workplaces in the suburbs. Theoretically, they could take a train to Southern Cross and transfer there to the airport service, but they’d be unlikely to do that for a number of reasons.
First, the journey would take too long – travellers would have to walk, drive or bus to their nearest station, transfer to a train or tram, and transfer again at Southern Cross station. Second, parking is inadequate – many would seek to drive to their nearest station, but there’re severe constraints on expanding parking in built-up areas. Limited economies of scale mean it would also be hard to provide an acceptable level of security for cars parked overnight at Melbourne’s 200+ rail stations. In addition, baggage would be problematic on peak hour public transport, which wasn’t designed with this purpose in mind. There would be delays in loading and unloading trains, trams and buses at rush hour and suitcases in aisles would reduce capacity.
Trying to leverage the existing suburban rail system would, in short, be too hard. Most Melburnians would simply continue to drive to the airport, leading to worse congestion. They would apply intense political pressure to have the freeway network expanded.
I’d like to offer a different solution. I think two key actions will be needed over the next twenty or so years. The first is to restrict access by car to the airport – unless there is a positive disincentive to driving (something less damaging than congestion!), alternative modes will not be viable. The second is to move the effective entry to the airport to multiple locations in the suburbs. Here’s a broad schematic of how I think it might work:
- Set charges that are high enough to discourage the great bulk of motorists from entering the airport or using the short term and long term car parks
- Provide an orbital transit service running from the airport to the west and to the south east along (mostly) existing freeways – see map
- Construct a small number of car parks with transit stations along this route, near freeway interchanges
- Aim to operate at a frequency and span of hours at least comparable to that currently provided by Skybus.
Under this scenario, Melburnians could drive to the ring road, park in a secure facility, and board the airport transit service. It would be little different from using the current long term car park and shuttle bus – the only real difference is the car leg would be shorter and the transit leg longer (although the overall time should be faster!). I also envision that ‘farewellers and greeters’ and taxi users would mostly go no further than the nearest transit station. The idea is the stations would be the effective ‘entry’ to the airport. Read the rest of this entry »
No way! If it weren’t for students we wouldn’t have flashmobs. I don’t know why, but they make me well up a bit. Here’s a collection of flashmobs dating from 2006 to last week. There’s even this one at Bondi Beach in 2009.
Workers who commute to Melbourne University at Parkville are much more inclined to use public transport than their colleagues who work at suburban Monash or Latrobe universities. The chart shows that at the 2006 Census, 41% of Melbourne University workers reported they drove to work compared to 83% at Monash and 84% at Latrobe universities. Many more staff at Melbourne also walked and cycled – 24% compared to 6-7% at the other two institutions.
Melbourne University’s lower car use is explained by a few key factors. The main one is that it is located on the edge of the CBD where car use is limited by high levels of traffic congestion and expensive all-day parking charges. For many staff, driving would take too long, generate too much angst and be too expensive. If the value of driving is marginal, the decision to choose an alternative will be tipped by the high quality of public transport service available to Parkville workers. Although it’s not served directly by rail (none of these universities are), Melbourne University has easy access by multiple tram lines to the CBD and thence to the many radial train and tram lines linking to the larger metropolitan area. For many Melbourne University workers public transport would be a no-brainer.
Melbourne University’s high level of walking can largely be attributed to the relatively high residential densities in the nearby CBD and inner city environs. If transport is expensive in outlays and time, it makes sense for workers to live close to the university. In this case, living close to the university also means living close to the many activities and opportunities offered by the inner city.
The suburban setting of Monash and Latrobe provides a very different environment. Although these universities are not without their challenges, they generally experience less traffic congestion and enjoy cheaper parking than Melbourne University. Low suburban residential densities and large open space and industrial uses mean fewer staff can live within walking distance. The level of public transport service is actually pretty reasonable by prevailing standards (for example, see here) but obviously not as good as Melbourne University, which benefits greatly from its proximity to the CBD. Read the rest of this entry »
I regularly hear the argument that time spent travelling on public transport is more enjoyable and more productive than time spent in the driver’s seat of a car. The public transport passenger can read, study, write, listen to music, play games, talk to others and even think without distraction. The driver, on the other hand, must devote most of his or her attention to the road or else get fined (or worse).
I think this line of argument is ultimately pointless. Both modes have their upsides and downsides in terms of how fruitfully in-vehicle travel time can be spent. Travellers make their choice on criteria that are far more critical than this one. Still, it’s an argument that’s often made so it’s worth looking briefly at the issues.
You can listen to music, podcasts and radio just as well while driving as you can on transit, so let’s scotch that one from the get-go. In fact some people prefer listening over speakers because ear phones can cause fatigue. And far too few smartphones and mp3 players come with AM radio, so if listening to 621 or 774 on the train is your thing then your options are limited. I’d score this one even.
What you can’t do in a car however is use a notebook computer, send text messages, play games or read reports and books, at least not if you’re driving. Actually notebooks aren’t widely used on public transport in my experience, even on the sharp end of planes, but reading, texting and playing games are certainly a common way to while away the time. It’s neither legal nor practical to do those activities in any meaningful way if you’re driving.
But they’re much harder to do on public transport if you don’t have a seat. On Melbourne’s public transport system that’s by no means guaranteed in rush hour. In places like Hong Kong, Singapore and Japan where public transport is the dominant mode, you don’t necessarily even get a choice (see picture – the priority there is to move lots of people quickly).
But there’s one area where the car has an offsetting advantage – (hands free) phone calls. Drivers can make personal and business calls without sacrificing privacy and without imposing on others. That means they can make more important, nuanced and meaningful calls than they would on a train or a bus. They can communicate more effectively without feeling self-conscious because strangers are listening in. Apart from the odd loudmouth, phone calls on public transport are like text messages – suitable mainly for communicating simple or straightforward information. Read the rest of this entry »
I like the (very) notional plans for redevelopment of the old E-Gate site in west Melbourne to accommodate up to 12,000 residents published in The Age (Thursday, 10 March, 2011).
Putting what might be 6,000–9,000 dwellings on 20 highly accessible hectares on the edge of the CBD makes a lot more sense than the mere 10,000–15,000 mooted for 200 hectares at Fishermans Bend.
But I do take issue with the claim by the Minister for Major Projects, Denis Napthine, that it’s a very significant development for Melbourne “because we want to grow the population without massively contributing to urban sprawl”.
The Age reinforces this take by titling its report “New city-edge suburb part of plan to curb urban sprawl” and goes on to say that it’s the first big part of the Government’s “plan to shift urban growth from Melbourne’s fringes to its heart”.
I’ve always liked the idea of E-Gate being redeveloped but, as I said on February 19 in relation to a similar report on proposals for Fishermans Bend, the significance or otherwise of the project for fringe growth has to be assessed in the context of the total housing task for Melbourne.
In the twelve months ending 30 September 2010, 42,509 dwellings were approved in the metropolitan area, of which around 17,000 were approved in the outer suburban Growth Area municipalities. That’s just for one year. E-Gate’s 6,000 – 9,000 dwellings would be released over a long time frame, probably at least ten years and quite possibly longer (the Government says Fishermans Bend will be developed over 20-30 years). Existing leases on the site run till 2014 so it’s likely the first residents won’t be moving in for a long time yet.
Of course it all helps but the contribution of the three redevelopment sites identified by the Government – E-Gate, Fishermans Bend and Richmond station – to diminishing pressure on the fringe will be modest. They don’t collectively constitute a sprawl-ameliorating strategy. Melbourne still needs a sensible approach to increasing multi-unit housing supply across the rest of the metropolitan area. The “brownfield strategy” is in danger of becoming “cargo cult urbanism”.
The State Government could strike a blow for cycling in this city if it were to declare Yarra Boulevard at Kew a ‘Bicycle Boulevard’.
This road is currently used by a range of recreational cyclists for riding and occasionally by some clubs for competitions. Although it doesn’t have heavy traffic there are enough cars and motorcycles to create a hazard for those on bicycles.
Drivers expect cyclists to ride single file within the marked lanes on the edge of the Boulevard. However this is difficult because of the number of cyclists using the road and the need to move onto the road proper (the ‘car lane’) to overtake slower riders. The bicycle lane is also rough with lots of gravel washed off the cliffs on the non river side.
At the moment, motorists ‘own’ Yarra Boulevard and ‘suffer’ the presence of cyclists. What I’m proposing is a reversal of that onus – cyclists would be the natural ‘owners’ of Yarra Boulevard and drivers would be required to behave as their ‘guests’.
The proposal is simple and low cost. Only a few actions are required:
- Install prominent signage indicating that the full width of Yarra Boulevard is a shared bicycle/car route with drivers obliged to give way to cyclists
- Declare a 30 km/h maximum speed limit for cars
- Paint out the existing cycle lanes and tear up the Copenhagen lane that was built along part of the route
- Provide an initial period of visible enforcement with occasional follow ups thereafter
I’m not sure if there might be legal issues involved with the concept of a bicycle route where cyclists have priority but if there are they need to be addressed. That would be an institutional investment – it’s likely that there will be increasing demand for these sorts of road sharing arrangements in the future. Read the rest of this entry »
We’re familiar enough with the idea of the ‘centre of gravity’ of population in Melbourne. But where is the centre of gravity of employment?
Is it the city centre? No, for one thing the CBD’s only got around 15% of all metropolitan jobs. For another, the combination of Melbourne’s distinctly lop-sided growth south of the Yarra and the fact that 72% of jobs are more than 5 km from the CBD, suggests it’s going to be somewhere south east of the CBD.
So I’ve calculated the location of the centre of gravity (more correctly, the ‘centre of mass’) of jobs from Census data. The accompanying chart shows how that location changed over the period from 1981 to 2006.
The centre of gravity is calculated by dividing Melbourne up into 1,000 traffic zones and weighting the coordinates of the centroid of each zone by the number of jobs it holds. If you imagine a relief model of employment in Melbourne, the centre of gravity is where you’d rest the model on a needle so that it balancess perfectly.
In 1981, the centre of mass of employment was 5.9 km east south east of the CBD, on Kooyong Rd, just north of Toorak Rd. By 2006 it was 7.9 km from the CBD, close to the corner of Malvern and Tooronga Rds.
This movement reflected the much stronger growth in jobs in the suburbs over this period compared to the CBD and inner city. Read the rest of this entry »
There are, but in Victoria those limits appear to be very elastic.
Because it controls the use of land, the whole complex edifice of planning regulation touches to a greater or lesser extent a lot of the things we do.
In a newly released report commissioned by COAG, the Productivity Commission gives us an insight into how the nation’s planning agencies think the land use control system influences our lives.
The report, Performance Benchmarking of Australian Business Regulation: Planning, Zoning and Development Assessments, examines the regulatory frameworks of each jurisdiction, the processes for supply of land, the bases for assessing developer contributions, compliance costs for business, and competition issues arising from planning decision-making.
As part of its investigations, the Commission asked each State and Territory to answer this question: “To what extent can government use the planning, zoning and DA system to positively influence the following challenges”?
The answers each jurisdiction provided to 23 “challenges”, graded from “no effect” through to “major effect”, are shown in the accompanying chart (copied from the report). The survey was completed between October and November 2010, prior to the Victorian State election.
Bear in mind that the survey relates specifically to the powers of land use planning agencies i.e. not transport or other agencies. Also, the planners were specifically asked about the scope to positively influence each of the challenges. There are some interesting claims here and some equally interesting comparisons between States and Territories.
There’s a consensus that, given (presumably) the right policies, land use planning can have a major positive influence on managing greenfield development, accommodating population growth, managing the transition to higher population densities, providing diverse/appropriate housing, and protecting biodiversity.
By and large I’d agree with that. My only caveat would be the understanding that some of the benefits will come from reducing rather than increasing the degree of planning intervention. A prime example is the many restrictions on constructing higher density housing within established urban areas.
Where the survey gets really interesting is outside these five key areas. Victoria in particular stands out from its peers. Read the rest of this entry »
Not necessarily – in fact in the US, not even usually!
It’s a truism that denser, more concentrated cities tend to have higher public transport use. Various studies have confirmed this intuition but what is usually left unexamined is the implicit assumption that such cities consequently have lower car use.
This study of 31 of the largest cities in the US found that assumption is not correct. Higher public transport mode share does not translate on average to lower kilometres of travel by car, shorter commutes by car, or lower levels of traffic congestion.
The primary finding “is that land use, at least at the aggregate level studied here, is not a major leverage point in the determination of overall population travel choices”.
Undertaken by Gary Barnes from the Centre for Transportation Studies at the University of Minnesota, the research found that, if anything, “the higher densities that increase transit share tend to increase commute times and congestion levels”.
The main objective of the project was to identify the effect of land use on travel behaviour. Most studies concentrate on the effect of average density on one or two variables, usually transit share and sometimes total kilometres of car travel.
Barnes’ approach was much more extensive. For each urbanised area, he defined 15 descriptors of travel behaviour, 11 of land use and 15 other, mainly demographic, factors. Moreover, he employed the concept of ‘weighted density’ (he calls it ‘perceived density’) to more accurately describe the distribution of both population and employment in each city.
Barnes confirms that residential concentration increases transit’s share of travel, but he notes the effect is not large. Contrary to the underlying assumptions of much urban policy:
Even very large changes in land use have very little impact on travel behaviour, in good ways or in bad. Apparently the larger effects sometimes observed in neighborhood-scale studies are just that: neighbourhood-scale effects that do not extend their benefits to the larger urbanized area.
His analysis implies that increasing residential density by 100% would increase transit share by only 5-6%. To get a 1% increase in walking and cycling’s combined mode share would require an increase in residential density of 5,000 persons/mile2 (1,931/km2). Similarly, a 14% increase in density would only yield a 0.5% decrease in in-car travel time per person. Read the rest of this entry »