Is this discounting any existing friction on the road and air resistance?
If it turns right at a road, without slowing down, it has gone acceleration. This is because when vehicles make turns, they need to apply a centripetal force, which causes the car to decelerate because their energy is applied to the turn and moving forward. The turn essentially slows the car down. However, if the bus/car/vehicle continues to move at the same velocity whilst making a turn, it needs to apply more speed (i.e. accelerate) to continue moving at its original speed AND complete the turn.
I hope that makes sense, I haven't touched prelim physics for almost half a year, but I'm quite confident the car does undergo acceleration of some sort to complete the turn and maintain its original velocity
