Schematic Transit Diagram vs Weather Map

スキーマティック路線図 / 天気図

Schematic Transit Diagram comes from Information Design and Weather Map from Diagrammatic Expression. One is layout and the other style. They are reached for with some of the same intent, which is where they get confused.

Schematic Transit Diagram

Schematic Transit Diagram — ベック以前の地理式地下鉄図 1908 — Wikimedia Commons / Public domainSchematic Transit Diagram — スキーマティック路線図の現代例（CC BY-SA 3.0）Schematic Transit Diagram — ベルリンUバーン 路線ダイアグラム — Wikimedia Commons / CC BY-SA 4.0

Discards geographic accuracy for horizontal, vertical and 45-degree lines with evenly spaced stations. Beck's 1933 London Underground diagram established it as the common language of transit maps worldwide.

Weather Map

Weather Map — 地上天気図 1947 — Wikimedia Commons / Public domainWeather Map — 『パーフェクト・ストーム』の解析図 1991 — Wikimedia Commons / Public domainWeather Map — フランシス・ゴルトン《イングランド同時刻天気図》 1861 — Wikimedia Commons / Public domain

The atmosphere drawn on one sheet with isobars, front symbols and weather signs. Making invisible pressure fields visible through the density of curves became the public's scientific graphic, from newspapers to television.

Schematic Transit DiagramWeather Map
Era1933–1851–
FamilyInformation DesignDiagrammatic Expression
KindLayoutStyle
CuesLines limited to 45 degrees / Evenly spaced stations / Color-coded lines / Independence from geographyThe density of isobars / Cold and warm front symbols / The weather-symbol system / Highs and lows labeled
Best used forReducing a complex network to what riders need, stations and interchanges · Showing a process or line where order matters more than geographyPutting an invisible field on one sheet as a continuous quantity · Designing a daily forecast graphic read the same way every time
TypeSet station names at one constant angle in a single face and sizeValues break into the isobar, set turned along the line
CompositionOnly horizontal, vertical and 45 degrees, even spacing, widened where stations crowdIsobars at one fixed interval, centers of high and low named
MaterialOne color per line, white circles for interchanges, plain background behindThe base map held pale, only lines and symbols brought forward
CautionTrying to keep a little geographic accuracy breaks the angle rule, and the diagram ends up neither accurate nor easy to read.Changing the isobar interval from day to day destroys the cue that lets a reader judge wind strength from how crowded the lines are.

Put these two together

Information Design ／ Diagrammatic Expression

IndexStyle