Mostly things I wrote on Mastodon but wanted to keep permanently.


Evaporative cooling and the size of vehicles


Thinking about the much declaimed rise of big cars/SUVs/utes in Sydney at the moment. I think there's probably an evaporative cooling effect (thanks that makes things look even worse than they 'are', in areas like mine.


Erskineville has really high rates of people cycling, walking and taking public transport to work. So who's left in vehicles? People who need them - so genuine tradie utes*, heavy vehicles, etc. And people whose identity is involved in driving and their vehicle, even when it's objectively expensive and inconvenient - and these people nowadays are overwhelmingly choosing high-fronted SUVs and 'trucks', rather than small fast cars which were perhaps once the status car of choice.


So we have streets where the parked cars, mostly used for occasional weekend trips, are a mix of smaller and older cars. But the vehicles actually passing me (as I stand at the bus stop musing) are on average larger.


Is this effect inevitable with any increase in sustainable mode share? 


Jed on Mastodon: "I think broadly, yes. If we imagine a perfect transport space where everyone takes the most efficient mode possible we would have almost no 'sedan' size vehicles on the road except taxis. Only bikes, motorbikes, buses, trucks of all sizes and trades vehicles, mostly utes and vans. Of course many of these *could* be smaller, but given the market and gov subsidies plus the need to have a vehicle that is big enough for the biggest job, not just right for the average, it makes sense that most people will opt for a large ranger/hilux etc."


Streets with entirely trucks, buses and trade vehicles versus bicycles and motorbikes are potentially going to feel weird and unpleasant - just because it's not the mix we are used to, or because it's genuinely problematic? The remaining vehicles are less safe for a cyclist or pedestrian to encounter, even if there are fewer vehicles (overall or per head). And they probably will not feel 'fewer' as this effect will be strongest in the most dense areas where the roads will always be full (unless road space is grossly oversupplied).


No conclusions here, just something I'm going to keep thinking about and observing.


*Not management, and I include my former job as a site engineer here, where I drove a Hilux around with rarely more than a hardhat and a clipboard in the back seat. Makes sense on a greenfield road job where you are driving off-road because you haven't built the road yet, doesn't make sense in city construction work, yet they still seem to be a common entitlement.