Why is oleander planted on the roadside?

It is generally planted next to Highway 2, with the purpose of dividing space and preventing pedestrians from approaching or crossing.

Oleander is poisonous, which can cause itchy skin and just block pedestrians.

In addition, safflower with strong applicability, extensive management and low content can be viewed, but special attention should be paid to its toxicity and it should not be used indiscriminately.