The McFurlong

Many widely accepted and understood units of measure are based on ubiquitous things. Examples include the teaspoon or the cup. Other more logically defined units (for instance the gram or the meter) are not as easily grasped by non-engineers. They are great for science but arguably less so for day-to-day use.

A common need when driving is to estimate distances and travel times. A difficulty posed here is you are isolated from what you are measuring---you can’t touch it like you can a teaspoon. Another problem is varying types of road and traffic congestion. Ten kilometers on a highway out in Montana is a very different thing than ten kilometers through downtown London.

What is needed is a simple, easily understood unit of distance that takes into account congestion. If such units were marked out on the roads using easily seen signs, estimating travel distances and times would come naturally.

Such signs already exist in the US and UK, and are rapidly being spread throughout the world. They feature a bright red field and a stylized “M” in yellow. They are the signs in front of McDonalds Restaurants.

I propose that the distance between these signs is “the McFurlong”. Not a precise unit of measure to be sure, but a good tool for your average Joe to roughly estimate the effort required to get from point A to point B.

Doing some back-of-the-napkin calculations, I see that there are over 30,000 McDonalds in the continental US, and over 1,000 in the UK. In both cases, this means the (again, very rough) average distance between two restaurants is on the order of 18 km.

Of course this assumes an even distribution of restaurants across the land, which is clearly not the case. The number drops to under a kilometer in congested city centers, and is considerably higher out in the boondocks. But the laws of economics insure that the spacing of these restaurants accurately represent the population density of their local areas, hence their congestion.

Conveniently, the McDonalds corporation has provided web based tools to calculate the number of McFurlongs between any two points, for both the US and UK. See links.