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User Model

The User Model is the component responsible for representing user behavior as an autonomous decision-making entity within MaaS Blender.

Events​

Consumed EventsEmitted Events
DEMANDRESERVE
RESERVEDDEPART
DEPARTED
ARRIVED

Role and Responsibilities​

The User Model governs how a user reacts to travel intentions, evaluates available options, and interacts with mobility services through events.

Its primary responsibilities are:

  • Receiving travel intentions as DEMAND events
  • Evaluating route candidates based on internal decision logic
  • Selecting a route and reserving the required mobility services
  • Managing the travel lifecycle by reacting to events emitted by mobility services
    (For details of the travel lifecycle, refer to User Event Cycle.)

Demand Handling and Route Selection​

The User Model begins its process upon receiving a DEMAND event, which represents the user’s intention to travel from an origin to a destination.

Based on the demand, the User Model evaluates multiple route candidates using its internal logic. Route candidates are typically computed using a Route Planner and then scored/filtered by the User Model. The evaluation strategy is pluggable and implementation-dependent. For example, the simplest logic may select the route with the shortest arrival time, while more advanced models may consider cost, transfers, or user preferences.

Once a route candidate is selected, the User Model proceeds to reserve the mobility services required for that route.

Reservation Flow​

To reserve a mobility service, the User Model emits a RESERVE event. This event is consumed by the corresponding mobility service.

Afterward, the User Model observes the RESERVED event emitted by the mobility service:

  • If the reservation fails, the User Model selects an alternative route candidate and retries the reservation process.
  • If the reservation succeeds and the user is able to start the trip, the User Model emits a DEPART event.

Trip Execution and Event Monitoring​

During the trip, the User Model may need to observe additional events emitted by mobility services, such as:

  • DEPARTED events, indicating that the mobility service has actually started
  • ARRIVED events, indicating that the user has reached a stop or destination

This monitoring is especially important in the following cases:

  • Transfers between mobility services When switching to another service, the User Model must issue a new DEPART event for the following leg of the journey.

  • Mobility services that do not support advance reservations In such cases, the User Model must wait until the user actually arrives at the service location before emitting a RESERVE event.

Through this event-driven interaction, the User Model continuously adapts the user’s behavior to the availability and state of mobility services throughout the trip.