Upon receiving an indication that a customer is initiating travel to a merchant location to pick up one or more items, sensor data may be obtained by, and received from, a customer device of the customer. After the customer has arrived at the merchant location, the customer may be greeted or otherwise interacted with and a corresponding interaction time may be determined. The service provider may identify one or more stop events based on the sensor data, where a stop event indicates that a customer stopped while in transit to the merchant location. A most recent stop event prior to the interaction time may constitute the customer arriving/stopping at the merchant location, and a corresponding arrival time may be estimated. A wait time of the customer may be determined based on a difference between the interaction time and the arrival time.