A City On A Grid Reads Faster Than A Tangled One

The first hours in an unfamiliar city are spent building a rough mental picture of it. How long that takes depends less on the city's size than on the shape of its streets.

What a grid gives you immediately

A grid encodes position. Two numbers or two street names fix a point, and the distance between any two points can be estimated without looking anything up.

That means a visitor can improvise. Deciding at four in the afternoon to walk somewhere new does not require stopping to work out whether it is realistic.

Grids also fail gracefully. A wrong turn puts you one block out rather than in a different quarter, and the correction costs a minute instead of a reroute.

Why older cores resist the same treatment

Street patterns that predate planning follow property lines, watercourses and the paths people already walked. They connect specific places to each other rather than covering an area evenly.

Such a network has no repeating unit, so there is nothing to generalise from. Knowing three streets tells you very little about the fourth.

The learning is done by landmark instead: a church tower, a wide junction, a particular bridge. That is slower to acquire and it collapses at night, when the landmarks are not visible.

The cost falls entirely on short trips

Somebody staying a fortnight absorbs the orientation period early and spends the remaining time moving efficiently. The overhead is real but it is amortised.

At two nights there is nothing to amortise it against. The visitor leaves at roughly the point where the place has become legible.

Tangled cities repay a different approach

The workaround is to stop trying to hold the whole plan and hold one line through it instead. A single spine street, learned properly, becomes the thing everything else is measured from.

Most old cores have such a spine, usually the route between the two things that mattered most historically. Following it end to end on the first evening is worth more than any viewpoint.

Everything then gets remembered as a turning off that line, which is how residents hold the same city, and it survives darkness better than a landmark does.

Neither layout is better to be in

Irregular street patterns produce the enclosure, the sudden openings and the changes of width that make a place pleasant to walk. Grids are efficient and frequently monotonous.

The point is not to prefer one but to budget for it. A tangled city at two nights wants a smaller ambition and a tighter radius than a gridded one of the same size.