When should reflective triangles be used?

Reflective triangles should be used whenever visibility is limited because they are designed to increase safety by alerting other drivers to the presence of a stopped vehicle. This includes situations such as poor lighting, inclement weather, or any other condition that hampers a vehicle's visibility. By placing reflective triangles, a driver ensures that they are warning oncoming traffic well in advance, reducing the chance of accidents.

Using them only at night would not account for daytime scenarios where visibility might still be poor, such as during rain or fog, which makes relying solely on nighttime usage inadequate. Additionally, while stopping on a hill may necessitate caution, it does not universally require the use of reflective triangles unless visibility is compromised. When heavy rain or fog occurs, it may indeed be necessary to use reflective triangles, but the broader guideline encompasses any situation where visibility is limited. Therefore, the comprehensive approach of using reflective triangles whenever visibility is compromised is the most accurate and safest practice.