The Case for Slow-Mo Driving

The EU law defines a certain type of vehicle as a moped that can be driven from the age of 15 with an AM type driver's license. These mopeds have two to four wheels, no more than 50 cc engine capacity (4.0 kW in case of electric engine), can drive no faster than 45 km/h (28 mph). I believe they may not exceed 450 kg of weight, fuel excluded, but a fast search hasn't confirmed that right now. The four wheel variety usually looks much like a Smart Car, which is very cute in a way.

But That's Not the Point

This post isn't about these mopeds, but the fact that I see them everywhere is one thing that inspired it. Because they're slow. And that is the point.

Over the course of the last week I've had three errands on different sides of town all about 10 to 20 km away. Let's call them A, B, and C. I haven't actually measured the distances; it's all estimates.

In the case of B driving a moped car there would take pretty much the same time. It's really traffic lights and congestion that costs time and most segments of the journey are limited to around 60 km/h with plenty of reasons to slow down anyway.

In both the other cases going 45 km/h instead of the speeds I can achieve with my "proper" car would cause significantly longer travel times. And those are only local distances. I still think reducing speed limits to 50 km/h would be worth it.

Speed is Costly In Both Lives and Energy

Low Tech Magazine had an article about the Citroën 2CV, comparing the 1949 model with the modern C1. The latter is vastly faster, more comfortable, and safer, of course. It's also vastly more fuel efficient, but they have virtually the same fuel expenditure per km. Why?

With the safety and comfort comes a huge amount of extra weight. About 300 kg of it, compared to the old 2CV. With extra weight comes extra fuel consumption. This is then extremely excarbated by increased speed.

Weight in itself scales energy spent for movement roughly linearly, because it mainly causes extra friction against the road. But speed causes extra wind resistance across a two-dimensional surface; the energy spent to maintain the same speed increases quadratically. In essence driving half the speed won't save you half the fuel; it'll save you closer to 75% of it!

Accidents at higher speeds are also more dangerous because of the forces involved. I dare suggest that accidents are also more common because our reaction speed hardly increases with velocity, though this is somewhat mitigated by safer road designs.

Imagine the reduction in our carbon footprint and serious traffic accidents if we reduced all speed limits to 50 km/h or slower. A guesstimate is that pollution from road transportation would be 50% lower.

But I Don't Wanna Go Slow

Neither do I, to be perfectly honest. A trip to my mom's place takes about 2.5 h today. Driving at a maximum of 50 km/h would almost double that. Transport of goods would also be much slower! Ugh. Once again personal comfort is pitted against climate. It doesn't have to be that way, though. All we need is extreme systemic change...

How To Make This Work: Trains, Rentals, Weight Reduction

Owning a car is a hassle already. It's expensive in so many ways: taxes, fuel, service and repairs, parking spots. Quite frankly I'd rather not own a car at all if possible, and I know I'm not the only one. Imagine adding horrible travel times on top of that. Especially regional and remote distances.

We could solve these problems though. Efficient, subsidised, and widespread train travel could take us far both fast and comfortably. Much more so than cramped cars, even. From experience I can say that there are things I'd rather do than spend twelve hours in a five seat car with four other people.

Trains cannot take us the last km to locations, however. There is still a need for other transport there. But if you only need a car for the first and last legs of a journey you could always rent in one or both locations. Cars made for shorter distances at lower speeds. That means less horse powers needed, less fuel volume needed (reducing the weight of a fully tanked vehicle), and for less time since most of the journey is done in climate friendlier ways.

Further reductions in weight can be made as well by removing commodities that we now take for granted. Sure, it would be less comfortable. But again only for shorter distances. The most drastic weight reductions can probably be made by removing safety measures; something that should not be taken lightly (no pun intended) but also not be ruled out. Safety is already improved by moving at lower speeds, and it's conceivable that some modern safety measures would add more weight than benefits. At these speeds a seat belt makes the most radical difference, after all.

In some circumstances the first and last legs of a journey could be made with electric velomobiles, which are a wopping 80 times more energy efficient than cars. These have no more safety than a bicycle, however.

On the Topic or Rural Living

I know my mom (among others) absolutely hates a proposal like this. Us city dwellers know nothing of the distances they face out in the rural lands!

She has about 30 to 40 km to the nearest town, which would end up costing her almost an hour in travel time. I know some people in the world have even a shitload longer. She also has a greater need for tools and materials for renovations, which makes having only a small car out of the question.

You know what? We could probably make some exceptions for these areas. They're already hit very hard by increased fuel costs though. Maybe it's time for some radical re-thinking of fuel economy there too? That's a different problem to solve, however.


Wikipedia article on mopeds.

"The Citroen 2CV: Cleantech from the 1940s" -- Low Tech Magazine.

Low Tech Magazine on the efficiency of velomobiles.

-- CC0 Björn Wärmedal