A logistics company uses a machine learning model to predict delivery times based on historical data. The model was performing well, but recently it started making inaccurate predictions, especially for routes that have experienced new traffic patterns and road closures. The data engineering team receives an alert that the model's accuracy has dropped by 15% over the last week. They suspect data drift. The team has access to the original training data and a continuous stream of new data. What is the most appropriate first step for the team to take?