Posts by David Haywood
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Okay, just making a more detailed response to DaveC’s comments...
I really didn’t want to get into the cycle lane vs. cycle path debate (a perennial topic in the engineering postgrad common room), as I see Copenhagenization as being about getting the numbers of cycle commuters to Copenhagen levels, and then reaping the economic benefits. The exact details of how you design the cycle infrastructure are just that: detail engineering. That said, of course, you don’t want to design a cycling disaster area (the Milton Keynes ‘Redway’ system is often cited as an example of this).
As DaveC points out, some cycle lanes can provide a safe environment. And, in fact, a number of studies have shown that some cycle paths are more dangerous than cycle lanes.
BUT:
Firstly, the ‘dangerous’ cycle paths cited in these studies seem to be examples of bad engineering design. In particular, the parts where the cycle path intersects with a conventional road. To me this is a design flaw in the intersection design, rather than being a flaw in the concept of the cycle path per se.
Secondly, the cycle lanes cited in these studies are (mostly) quite different from what we call cycle lanes in New Zealand. For example, the cycle lanes near my neighbourhood in Christchurch are 1 metre in width (I’ve just measured them). In Denmark, the minimum standard width is 2.5 metres (older lanes are 2.2 metres). Internationally the standard recommended width seems to be at least 2 metres, with an absolute minimum of 1.5 metres. My take on the cycle width recommendations in other countries is that – on the surface of it – ‘skinny’ cycle lanes don’t offer much more safety than no lanes at all. Indeed, there have been studies suggesting that they are more dangerous than no cycle lanes (although I personally don’t find this conclusion very convincing).
Furthermore, the cycle lanes in Denmark are slightly raised from the road (approximately half-way between kerb height and road surface height). Similarly, lots of Dutch cycle lanes have some sort of physical (not just paint) marking that separate the cycle lane from the road proper. Indeed, I think that in New Zealand we would actually regard Danish cycle lanes as cycle paths (that happen to run beside the road).
So we’re not necessarily comparing apples with apples if we apply these studies to Christchurch.
Having criticized our skinny cycle lanes in Christchurch, I would still much prefer them to no cycle lanes at all. My personal experience (not a scientific study) is that motorists often become enraged when they perceive that cyclists are on their territory, i.e. on the road. By having a ‘declared’ cyclist territory this appears to have a beneficial psychological effect upon Christchurch motorists, making them happier to have cyclists on the road. Having had motorists throw everything at me from abuse to eggs to an (empty!) vodka bottle, I appreciate something that will sooth them a little.
If you want my opinion on the mix of cycle systems that we should consider for Christchurch (bearing in my that traffic engineering is not my field).
1. Conversion of some conventional roads into nominated cycle roads that limit (or ban) motorized through-traffic, have a 30 kilometre per hour speed limit, and wide Danish-style cycle lanes.
2. For busy roads (that are already controlled by traffic lights) use wide Danish-style cycle lanes – but where the width isn’t feasible, use narrower Danish-style cycle paths. Both lanes and paths should go through the conventional traffic light system with cyclists getting their own signal (a number of the cycle paths going through Christchurch’s Hagley Park already do this).
3. Where Danish-style cycle paths or lanes are impractical then use New Zealand style ‘skinny’ cycle lanes.
4. In all cases, where possible, route the cycle lanes and cycle paths through Christchurch’s numerous parks. Again, careful intersection design is needed where these rejoin the normal road.
Which is about all that I should say on this topic.
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I've just modified the 'What sort of cycling infrastructure should we build?' section of this post (actually just restored some deleted bits from an earlier draft). Hopefully this will makes things clearer in response to DaveC's earlier comment.
I didn't want to get into the whole cycle paths vs. lanes debate, but I will do so as soon as I get my son to sleep -- if I ever do (we've been trying since 6.30 pm).
More later...
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I didn't realize this thread was still going, but am impressed that a couple of people are continuing the long tradition of assuming that I must be an idiot...
Kyle Matthews: I used to teach thermodynamics at UoC -- so no, I don't think that you can 'cool' an icerink with river water at 8 degC! As Ross pointed out, I was talking about the improvement in performance from rejecting heat (from the hot heat-exchanger on the refrigeration plant) into river water. This would mean that the refrigeration plant was operating over at least an 8 K smaller temperature difference than if rejecting heat to a gas such as air. Which would mean a significantly higher COP and a proportionally smaller electricity bill.
Ralph Boardman: no, I didn't forget about sea-level rise, but it's not relevant to the discussion of abandoning 100 metres around the river bank. Sea level rise would affect some of the lower river, but equally all the land surrounding it -- not just the nearest 100 metres. It wouldn't affect the upper river.
In the event of this sort of sea level rise (the CCC were talking about 500 mm, last time I checked) it would be almost certainly be cheaper to build a dyke than abandon most of East Christchurch. While we're at it maybe we should make the dyke a tsunami wall -- I've just been looking at the possible effects of a tsunami on CHCH.
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Southerly: One Hundred and Thirty-one…, in reply to DaveC,
painted cycle lanes do increase cyclist safety. Segregated cycleways that have road intersections are often no better from a safety point of view, and in some cases worse, than cyclists using the road.
Sorry that probably wasn’t clear, DaveC. I was referring to CHCH cycle lanes. Lots of that cycle lane vs. path research is based on European cycle lanes which are much wider than we have in CHCH. In fact, I’ve been told by a visiting German traffic engineer that lanes less than 2 metres in width (i.e. practically all cycle lanes in CHCH) offered no safety benefit at all. And I’ve seen at least one study that suggest that narrow cycle lanes are more dangerous than having none. Dr Koorey at UoC has a nice review paper on this which I’ll link to when I get home.
And yes, excellent point about intersections on cycle paths and cycle roads. I was going to talk about this exact issue with Kathryn Ryan (honest!) but she diverted me onto another topic at the last moment.
Christchurch has made a start on cycle infrastructure, no argument (and the cycle path beside the railway line is excellent). But you can’t really build half a cycle infrastructure (or more like 5 per cent) and expect a major increase in cycle commuting – and the consequent economic benefits.
Sometimes (quite often, actually) the gold-plate solution is cheaper than the lead-plated solution over the long term. Mind you, you need to be very sure that it is really gold on your gold-plate solution.
More when I get home…
Thanks,
David -
Southerly: One Hundred and Thirty-one…, in reply to MikeE,
Considering the vast majority of petrol costs is taxation, wouldn't that figure of 34 million going offshore be a bit misleading..
I certainly didn't say it would all be going offshore -- I said a "significant proportion" of it would. It's difficult to find exact numbers (it depends on the retailer) but -- from memory -- it's at least 25 per cent in all cases. I'm on my bike going into Radio NZ now (on at 11.45 am), so can't check my notes.
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Some very interesting comments here – just a quick reply to one or two while my son has his shower:
Lucy Stewart wrote:
All that said, though, it won’t replace car ownership. People own cars in Christchurch because it’s spread-out, and if they want to socialise or have options while shopping, you need a car.
Agreed – that’s why I didn’t take that into account. But, as you say, I do think it’s very possible that many households would give up their second car in the event of widespread cycle commuting, which would still be a major saving to both them and the Christchurch economy (a savings that I haven’t considered in these numbers).
Paul Campbell wrote:
… can they do something about the wind that blows from the Uni in the mornings and towards it in the afternoons?
Oh, I know that wind. As one of my friends said: it’s not just the extra physical exertion, it’s the thought of all that entropy generation and its reminder of the eventual death of the universe.
stephen walker wrote:
... maybe some subsidies for certain types of equipment would be in order (lights, rain gear, helmets, etc.)?
That's certainly something that could be integrated into a 'reverse toll' system (if you wanted to go that way). For example, if you could work out your road maintenance savings per kilometre per cyclist then there's no reason that this couldn't be paid directly to the cyclists.
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Hard News: Three months after, in reply to Clarke,
Yet reading Russell’s post is just so depressing – 3 months later and there seems to be so little happening.
I see that Lilith has beaten me to a response -- to back her up: the work done so far has been massive; almost unbelievably so. We just have lots more of the same still to go.
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Hard News: Three months after, in reply to Islander,
Dear David H – among the ‘munted’ (jeez I hate that word with it’ s S.African nasty origins) family houses, are ones that include heavily mortgaged family groups.
I'm very sorry to hear that, Islander. I fear that there's going to be a lot of financial stress in CHCH in the coming months: a perfect storm of earthquake-related job losses and the inability to sell damaged houses. Gerry Brownlee will have a lot on his plate.
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Thanks for a great post, Russell (not to mention a lovely visit). Yes, I should have written something like this myself, but it's just so damned depressing that I couldn't even bring myself to think about it.
I did enjoy your description of our house as "okay". The damage runs to more than $200,000 -- but you're dead right! Compared with many of our neighbours (particularly those with houses built in the last 30 years), our house is both livable and ultimately repairable. We could be in a much worse situation.
The other reason I didn't want to write about this (except tucked away as a comment on your post) is that I'd have felt compelled to mention how defeatist the mood is at the moment. The vast majority of people I talk to around here have already accepted that CERA will be a disaster and that CHCH will never recover. As a neighbour put it: "Brownlee is gonna fuck us all over, and Christchurch is gonna be a permanent fucking disaster. When I get the insurance money I'm moving to Australia -- and the quicker people realize that's the smart move, the happier they'll be."
I suspect that we will have to fight for a lot of things -- but that this sort of defeatist attitude will only make things worse. And, in fact, could be the thing that does ultimately produce failure. (Although I know that some of my neighbours think I'm quite out-of-touch with reality to be cheerful in any way.)
For this reason, I must say that I was greatly heartened by Gregor Ronald's comment above. Nice to see some optimism -- even if you and I may be the only ones in the neighbourhood.
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Southerly: That CERA Rumour, in reply to Kyle Matthews,
You may not be aware that they had an ice-rink in Cathedral Square last winter (in a tent) -- it was brilliant, in my opinion.
If you moved it 300 metres up Colombo Street to Victoria Square, you could use the Avon River as your heat sink. The Avon stays cooler than 8 deg C throughout winter, and the low heat rejection temperature coupled with the superior heat transfer properties of water (in comparison to air heat rejection) would make for about as efficient a refrigeration system as you could design for those conditions.
Not necessarily endorsing the idea, but it's the first thing you'd think of as a mechanical engineer (as Roger Sutton is).