What is the difference between the following traffic signs?

- There is no difference between them.
- Traffic sign 306 alerts about a pedestrian crossing ahead, while traffic sign 135 marks the place of the crossing.
- Traffic sign 135 is placed in non-urban roads, while traffic sign 306 is placed in freeways.
- Correct answer: Traffic sign 135 alerts about a pedestrian crossing ahead, while traffic sign 306 marks the place of the crossing.
Why this is the answer
The correct answer in the official bank: Traffic sign 135 alerts about a pedestrian crossing ahead, while traffic sign 306 marks the place of the crossing.
A red-bordered triangle is a warning sign, so sign 135 stands before the crossing and alerts you that one is ahead. The blue square sign 306 is an information sign placed at the crossing itself. Slow down when you see the triangle and be ready to give way to pedestrians. The difference has nothing to do with the type of road.