How much does rain reduce bike-share use?

AI SLAI HL Solid Also in: Statistics

Research question

How are daily journeys on London's cycle-hire scheme related to temperature and rainfall, and is the effect of rain significant after allowing for temperature and weekends?

Adapt it: change the place, the data or the comparison until the question is yours.

Why it makes a good exploration

Transport planners need to know how weather affects demand. TfL publishes every hire journey, so you can build a weather model with a huge, real dataset.

The mathematics you'll need

Regression and correlation
Comparing groups (rainy vs dry days) with t-tests
Controlling for a variable by splitting the data
Spearman's rank for non-linear effects

Course labels show where a technique sits; using maths from outside your course is fine if you explain it clearly and say it is new to you.

Where the data comes from

Daily journey counts from TfL open data and daily weather from the Met Office or a local weather archive.

Transport for London open data — Timetables, station entry/exit counts, cycle-hire journeys and air quality for London.
Met Office historic station data — Monthly max/min temperature, rainfall, frost days and sunshine for 37 UK stations, some from 1853.

Cite every source in a footnote where you use it and in your bibliography. Check the licence of any dataset you download.

A possible outline

Aggregate journeys by day.
Explore temperature and rain separately.
Compare rainy and dry days within similar temperatures.
Consider weekday vs weekend.
Reflect on strikes, events and seasonal effects.

Pitfalls that cost marks

Mixing weekdays and weekends.
Defining a rainy day inconsistently.
Ignoring outliers from tube strikes.

Showing personal engagement

Compare with your own cycling habits.
Choose a question for a city you know.
Predict demand for tomorrow's forecast and check.

See Criterion C: personal engagement for what examiners look for.

Taking it further

Model journeys with both temperature and rain in a multiple regression (explain the new maths).

Turn this idea into your IA

Plan this IAOpens the planner with this question, the maths and data sources filled in. Desmos workspacePlot your data, fit models and keep your graphs with your plan. AI feedback on a draftCriterion-by-criterion feedback with evidence from your own text. Coaching, not rewriting. Examiner reviewPete, a practising IA examiner, reads your draft and talks it through with you (€100).