Modal Split Estimate Calculator

Work out modal split estimate instantly with clear inputs, formula shown and shareable results.

About Modal Split Estimate Calculator

Modal split allocates total trips between modes. Because the entered shares rarely sum to exactly one hundred percent in practice, they are normalised before being applied, and the raw sum is reported so any data error is visible. Car trips are the figure that converts into road capacity and parking demand.

Formula

Modal split

Trips by mode = total trips x mode share / sum of shares entered

Worked example

With the default values below, Modal Split Estimate Calculator returns Car trips of 4,500. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total daily tripsminimum 1 trips: 10,000 trips
Car shareaccepts 0–100 %: 45 %
Public transport shareaccepts 0–100 %: 30 %
Walk and cycle shareaccepts 0–100 %: 25 %

Results

Car trips: 4,500 trips
Public transport trips: 3,000 trips
Walk and cycle trips: 2,500 trips
Sum of the shares entered: 100.00% %

Step by step

1Values used
2Modal split
3Car trips= 4,500 trips
4Public transport trips= 3,000 trips
5Walk and cycle trips= 2,500 trips
6Sum of the shares entered= 100.00 %

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Modal Split Estimate figure worked out?

Trips by mode = total trips x mode share / sum of shares entered. Modal split allocates total trips between modes.

Why normalise rather than reject the input?

Survey shares often omit minor modes or double count linked trips. Normalising preserves the relative proportions, which is what the modelling actually depends on.

What values do I need to enter?

This calculator takes 4 inputs: Total daily trips, Car share, Public transport share, Walk and cycle share. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.