Which statement about outdoor mobile robots (such as delivery robots) under the Road Traffic Act is correct?

1. ①An outdoor mobile robot is a 'vehicle', so it must travel on the roadway, not the sidewalk
2. ②Even if an outdoor mobile robot breaks traffic rules, the operator who controls it remotely bears no responsibility at all
3. ③An outdoor mobile robot is not included among pedestrians, so it cannot be operated on a sidewalk
4. ④The operator of an outdoor mobile robot must handle its controls accurately and must not operate it in a way that endangers or obstructs vehicles or other people