Southerly by David Haywood


One Hundred and Thirty-one Million Reasons to Copenhagenize Christchurch

Perhaps the most common theme on the website (a council-run service for collecting ideas on the rebuilding of central Christchurch) is the suggestion to dramatically improve the city's cycling infrastructure. Although only one submission actually mentions the word 'Copenhagenize', this would be the verb that many engineers would employ to describe the overall process of designing a cycle-friendly city.

If you haven't come across it before, 'Copenhagenize' arises from an urban planning philosophy that was implemented in Copenhagen in order to promote the use of bicycles (and also walking) as a form of urban transportation. The success of this planning philosophy in Copenhagen has been astounding -- with 36 per cent of its population now making their daily commute by bicycle.

The website only permits a maximum of 140 characters for each submission, which doesn't allow a lot of room to explain why Copenhagenization might be a good idea. So I thought it might be worth giving a quick overview of the research on this topic.

What was the original inspiration for Copenhagenization?

Copenhagen's flat landscape makes it ideally suited to cycling, and for the first half of the 20th century the bicycle was the most popular form of personal transportation (excluding walking).

During the 1960s, however, the increasing affordability of motor cars led to a decline in cycling, and it was only with the 1970s energy crises that the city began to consider ways of getting its citizens back onto bicycles -- as a means of reducing fuel usage and curbing air pollution.

In order to achieve this, the local government in Copenhagen adopted a policy of encouraging cycling via a safe, convenient, and widespread cycling infrastructure.

But isn't the natural geography and climate of Copenhagen much more suited to cycling than Christchurch?

In terms of natural geography, both Copenhagen and Christchurch (apart from a couple of hill suburbs) are extremely flat cities that are equally well-suited to cycling. But -- from a cyclist's perspective -- Christchurch actually trumps Copenhagen in the crucial climate data with:

  • A much warmer winter (average winter temperature of 9 degrees Celsius in Christchurch as opposed to 0 degrees Celsius in Copenhagen).
  • Much lower annual rainfall (an average of 360 millimetres in Christchurch as opposed to 587 mm in Copenhagen).
  • More sunshine hours (an average of 2,025 sunshine hours in Christchurch as opposed to 1,603 sunshine hours in Copenhagen).

In fact, in terms of suitability for cycling, the only advantage that Copenhagen has over Canterbury is the cycling infrastructure.

Okay, but what advantages would Copenhagenization give to Christchurch?

Short answer: it will save us loads of money.

Despite being so suitable for cycling, Christchurch has the highest car ownership rate of any city in New Zealand and over three-quarters of the working population commutes in a private motor vehicle (only six per cent of Christchurch commuters travelled by bicycle on census day March 2007).

If the citizens of Christchurch cycled at the same rate as those of Copenhagen (given Christchurch's employed population of 162,243, our median commuting distance of 5 kilometres, the typical New Zealand vehicle's fuel consumption of 10 litres per 100 kilometres (with a conversion factor of 1.25 to convert from 'combined' to 'urban' fuel consumption)) then this would save the annual equivalent of 14.6 million litres of 91-octane petrol.

At current retail fuel prices, this equates to nearly 31.4 million dollars per year -- a significant proportion of which would have been sent overseas (with a detrimental effect on New Zealand's balance of payments). According to the NZTA, the increased population of cyclists would also save about 11.7 million dollars per annum in "environmental benefits" such as congestion reduction and decreased vehicle emissions (the NZTA values these at $0.10 per kilometre for each motorist taken off the road during peak traffic conditions).

In other words, the Christchurch economy would have to pay about 43 million dollars less each year in fuel and environmental costs to get its citizens to and from their place of work.

This seems enough of a reason to take a closer look at the possibility of Copenhagenizing Christchurch, but the health effects of cycling are where the real savings to the economy start to kick in. A NZTA research report from 2007 carried out an in-depth investigation into the economic health benefits of various forms of 'active' transport -- examining the preventative effects on diseases such as diabetes, cancer, coronary disease, and even depression. Assuming that the same proportions of physically active people in the general population are also represented in cycle commuters, then the monetary value of encouraging the citizens of Christchurch to cycle like Copenhageners amounts to an astonishing 87.5 million dollars per annum.

Are you keeping track of all this? Add it all together and you get a total savings to the economy of 131 million dollars per year -- quite a sizeable chunk of change for a small city (in which, by comparison, the city council's 2010 rates revenue is only 256 million dollars). And this is not even to consider such items as reduced road maintenance, vehicle repairs/maintenance, and parking costs.

But wouldn't it take much longer to commute by bicycle?

It would depend. In my experience with a regular 11.5 kilometre (each way) commute during Christchurch's rush hour, it only took five minutes longer to travel by bicycle than in a car. On a bicycle you can pass an awful lot of motor vehicles queued at traffic lights.

But a better way to answer this question would be to consider the length of time that people consider reasonable as a commute. The average commuting time (one-way) in New Zealand is 20 minutes, which is probably a good indication of what Christchurch citizens might tolerate.

It's difficult to estimate how fast an average person would cycle when commuting in Christchurch, but the average cycling speed through urban areas in Holland is 15 kilometres per hour. Using this figure we can predict that the average commuting cyclist would likely travel five kilometres in the average New Zealand commuting time of 20 minutes.

And conveniently, as mentioned already, five kilometres is the median distance commuted in Christchurch. So, on this basis, the length of time that would be spent commuting by bicycle in Christchurch should be entirely acceptable.

So how real are these numbers?

There are a lot of unknowns in assigning economic costs when dealing with the unpredictable human personality (and I'm always slightly suspicious of such studies). For example, it's possible that significantly fewer people would cycle when it's either very hot or very cold, or -- despite the excellent rain-gear now available -- on the comparatively few rainy days in Christchurch. This would have the effect of reducing the economic savings given above.

On the other hand, it's very likely that the census data grossly overestimates the number of existing cycle commuters in Christchurch. It's also likely that a significant proportion of people may dispense with their second car when they start to commute by bicycle (saving at least $1,500 per year per household in depreciation, registration, WOF, repairs, and maintenance) -- which would have the effect of markedly increasing the savings given above. Furthermore, the 'employed' population used in these calculations does not include the 19,000 students enrolled at the university of Canterbury or the 20,000 students enrolled at CPIT, which could increase the annual savings by as much as 30 million dollars.

Another possibility is that only very physically fit people would commute by bicycle, which would significantly reduce the economic health benefits. But when you look at cities such as Amsterdam or Copenhagen or Munich you see a very broad range of cyclists -- from octogenarians to new-born babies (in carriers) and people of every size and shape. It's hard to see why Christchurch would be so different.

And, of course, there is likely to be a mismatch between the median distance commuted by a predominantly motoring workforce versus a bicycle community. My suspicion is that those with the shortest commuting distance would be more likely to 'convert' to cycling. But it must be remembered that these calculations are only for pure commuting travel -- it doesn't include weekend journeys or diversions to run errands while commuting, which are more likely to be undertaken on a bicycle when people are already regular cycle commuters.

In short, the numbers given are a ballpark figure: the true value could easily be plus or minus 50 per cent.

What sort of cycling infrastructure should we build?

Like Copenhagen, we need to build cycle infrastructure that will keep cyclists safe, that will be convenient for cyclists to use, and that is widely spread across the city so that cyclists can get where they need to go. This includes:

  • Building cycle paths that will safely separate bicycles from motor traffic -- in addition to the current cycle lanes (which are just painted markings on main roads). With 600 kilometres of post-earthquake road repairs required in Christchurch there may never be a cheaper time to do this.

    Above: A proper cycle path in Copenhagen.

  • Building green corridors to route cyclists through the (more than 740) parks in Christchurch. This would help to separate bicycle commuters from car exhaust fumes (from my own experience with cycle commuting I know that I'd rather take a slightly longer path through a park than a shorter route via a car-clogged street).
  • Build the necessary traffic lights and cycle parking for bicycle commuters. And, as much as possible, integrate cycling with the public transport system (as is already done on the Lyttelton ferry and buses).
  • Consider designating some streets to be 'cycle roads'. This would involve closing the roads to motorized through-traffic, designating a 30 kilometre per hour speed limit for residents and delivery vehicles, and marking-out large cycle lanes that physically dominate the road. This is a very low-cost option (indeed it would reduce the cost of maintaining existing roads) that will never be cheaper than in the post-earthquake rebuild.
  • Consider some radical approaches to encourage commuting by bicycle. For example, it would be technically possible to 'reverse toll' cyclists (in conjunction with the existing Metro card system) using electronic readers on cycle paths. Cycle commuters could then be rewarded with free bus travel that could be used for longer journeys or during bad weather.

Of course, for cycle paths, cycle lanes, and green corridors it is critically important that they should connect to the existing roading network in a safe manner.  Most accidents occur at intersections, and a properly-designed cycle infrastructure will make use of a variety of sytems to meet the distinct requirements at any given location.  No system is inherently safer than another (a good overview of cycle infrastructure design as it relates to Christchurch is given here; some of my own thoughts on this topic are here).

In conclusion

The Copehagenization of Christchurch would bring very significant economic savings to the economy (in the ballpark of $131,000,000 per year, according to my calculations). But, as Copenhagen has proven, we will need to build the cycle infrastructure first, and use this as the 'bait' to encourage commuting by bicycle so that we can reap the economic benefits. One thing that we have already conclusively proven in Christchurch is that poor cycling infrastructure will never persuade our citizens to get on their bikes.

Listen to a discussion of this post with Kathyrn Ryan on Radio New Zealand

Oh, and in only somewhat related news for Christchurch residents:

There is now a website to help children to cope with earthquake-related trauma. It looks like it could be a useful resource.

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