ModalSplit

Modal split, or mode share, is the distribution of transportation activity by mode within a defined geographic area and time period. It expresses the share of trips, person-kilometers, or total travelers using each mode, typically shown as percentages. Commonly compared categories include private cars, public transit, walking, cycling, and sometimes taxis, motorcycles, or air travel. Measurements can be trip-based or distance-based, and results depend on definitions, data sources, and geographic scope.

Measurement methods rely on travel surveys, census data, traffic counts, transit ridership records, and increasingly passive data from smart cards, GPS devices, or mobile phones. Modes are categorized consistently, and results may be reported for a city, region, or corridor. The distinction between trip-based and distance-based shares and the treatment of multi-modal trips are important for interpretation.

Uses of modal split include informing urban planning, transportation modeling, and policy evaluation. Changes in mode share help assess the impact of interventions such as new transit service, pricing schemes, parking policies, or land-use changes. Modal split is also used in monitoring sustainability and climate objectives by evaluating reliance on low-emission or active modes.

Factors influencing modal split are diverse, including urban form (density, land-use mix, street network), transit service level and reliability, travel times, costs, safety, comfort, and cultural preferences. Policy measures to influence mode share include congestion pricing, parking management, investments in transit and non-motorized infrastructure, and incentives for non-car travel.

Limitations include its aggregation and variability over time and place. Data quality, mode classification, and whether the measure reflects trips or distances can affect interpretation.