(b) The foregoing limitations shall not apply to the driver of a vehicle turning left while entering or leaving such highway.
(c) Where a two-way left turn lane or a paved and clearly traversible dividing section separates the travel lanes for traffic proceeding in opposite directions, the foregoing limitation shall not apply to the driver of a vehicle traveling within such lane or section for such distance as is required for safety in preparing to turn left leaving such highway or in completing a left turn entering such highway.