Low carbon transport part 2: The car is not the devil. Empty space in them is.

When I talk about the sustainable transport/low carbon transport thing I often get accused of having “car hatred” going on. It seems that no matter who the audience there is always a Jeremy Clarkson there accusing me of lack of reason, idealism (since when did that become a swear word?) or just plain spoiling-the-party. There is a grain of truth in the accusations. It’s true that I don’t get the speed fetish thing. I also don’t really get the car-as-sex-object; car-as-status symbol thing either. But just because I don’t get the emotional attachment which many have to their cars and all that they stand for, it does not mean I have a blanket opposition to them.

In the last post I wrote of the 70% of transport energy consumed by the cars making 25% of trips. The simple reason for this imbalance is that cars are a highly inefficient way of moving people around. Looking at it in basic terms we regularly energise about one ton of metal with petrol in order to move an 80kg human around. Mad! Even though buses and trains are bulky and lumbering the numbers of people who can squish into them mean that they are super energy efficient per trip. The key to really understanding energy efficiency in transport is to wrap your head around the difference that occupancy makes.

Source: Cape Town Partnership

Source: Cape Town Partnership

This graphic shows the intuitively obvious. Quadruple the people being carried and quarter the energy use and associated emissions. Which is just one reason why liftclubs and technologies which encourage shared use are worth encouraging.

Perhaps more interesting, though, is that in the short term in South Africa (thanks largely to the nature of our segregated, sprawling cities) cars could be an important tools in carbon reduction. Full cars can be almost as energy efficient as the most energy efficient public transport mode – the minibus taxi. This is because a car-pooled private car will tend to travel one way full, park, and then return home full again. By contrast a minibus taxi (like all public transport in South Africa) may well travel full in one direction during the commuter peaks and then be almost empty on the return journey. The distorted land patterns in South Africa which keep employment far away from residences, with very little mixed uses of activities inbetween is terrible for efficient public transport use. This separation of activity makes for imbalanced flows of people and inefficient empty public transport vehicles. A mix of activities in a city means that the public transport system can be better used…saving money on the “return” legs.

So even when I am wearing my most strident energy efficient hat I’m not a car-hater, but I am an empty seat hater.

 

 

 

 

 

 

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