Car Mass Transit: The True Cost

The problem with cars is that they are too heavy. They have revolutionized western life, democratizing transport, transforming urban design and the way we shop for our vegetables. They have increased our capability to transport goods on a personal scale to a level previously unimaginable in human history. Therein lays the miracle, and the problem.

There have been entire years where my golf clubs have been effectively stored in the back of my car, taken out occasionally for use and re-deposited in the trunk.

Imagine if, when you walked down the street to the corner store that you adopted the same approach, walking around town on a Sunday afternoon with a bag full of golf clubs on your back. What do you think the end result would be?

You'd be more tired and needing more frequent stops for water and food-fuel. On hot days, the prospect of having to carry your clubs might be enough to stop you from going out for that walk at all.

What do you think the net effect would be if you left those clubs in the back of your car full-time? Simple physics dictates that more work is done by the car, and that by extension, more energy is consumed in the process. While your car does not have the property of 'tiredness', I'm guessing that you'll need to fuel up more frequently with the clubs in the cart.

Beyond the micro economic concern arising from higher fuel expense - especially at the end of what may have been the era of cheap fuel - this system-wide performance hit could have significant consequences. While it’s true that if every car on the road had an extra set of golf clubs in it, overall fuel consumption of nations would go up, I think there's a more insidious systemic issue lying in the weeds here.

Consider the other overhead items that constitute the typical family car - the kind that we so often see in morning 'work traffic' with just one occupant, the driver.

The whole back seat

The family car is designed to carry between one and ten or more people and they have the seating to do it. Imagine again, that you're out for your Sunday walk, and along with your golf clubs, you decide to bring along seating for three of your friends in the form of a sofa! With pounds of foam and springs, piles of wood AND your bag of golf sticks, would you make it past your local Starbucks?

A spare tire

It’s nice to have a backup plan. Traffic engineers and urban designers would argue that, without the possibility for local and autonomous repair for the inevitable flatty, traffic systems would grind to a halt. But consider for a moment that your 25 pound spare tire represents approximately 0.5% of the mass of your typical small car. That means that the system is paying a weighty and hence energy-consuming penalty to carry tonnes of rarely used rubber and steel. Is the cost worth it? Is there a better way? Perhaps you should just add a spare set of shoes to your list of Sunday afternoon carry-on items.

The sound system and drink holders

These items are staples for any family car, and I think quite reasonably so. But again, add a ghetto blaster to your back and go for a walk, and you'll soon feel the true cost of carrying a fully featured sound system everywhere you go.

The true cost

And that is the point I believe. Not that we should get rid of back seats or spare tires. Or even that by taking some of the extra junk out of our cars that we might be able to take a free bite out of our Kyoto obligations. But that costs of a transportation infrastructure based on the personal automobile have been hidden from us.

This is not a direct argument for rethinking our transportation infrastructure, although the massive emerging markets in China and India may force that rethink anyway. It’s an observation that the convenience of the modern car has obscured the amount of work these machines do for us and how much 'wasted energy' they consume. This is truly remarkable when compared to the workload and energy consumption of vehicles throughout the history of transportation.

A recent car commercial features a medieval village celebrating with stereotypical wooden mugs and fire roasted meat. To the surprise and joy of the revelers, a gift is spotted outside the gates to the village - a shiny red, compact car. The drawbridge is opened, the car is driven into the village, and the party is continued long into the evening. Fade to black, and the following morning sees the many revelers passed out around the car. The car doors are opened a crack, and out pours an army's worth of invaders to take over the town, Trojan style, highlighting the voluminous cargo carrying capacity of the car.

Democratization indeed, but can we afford it for all.