John drives 16.0 km directly west from Orion to Chester at a speed of 87.0 km/h, and then directly south for 8.00 km to Seiling at a speed of 80.0 km/h, and then finally 34.0 km southeast to Oakwood at a speed of 100 km/h. Assume that he travels at constant velocity during each of the three segments. What was the change in magnitude of velocity during this trip? (Hint: Do not assume that he starts from rest and stops at the end.)