When should a signalperson prefer radio communication over hand signals?

A signalperson should prefer radio communication over hand signals primarily when visual contact is lost or in noisy environments. In situations where the operator cannot see the signalperson, such as around blind spots or obstructions, radio communication becomes essential to ensure safe and effective coordination. Additionally, in noisy environments, hand signals may not be visible or easily interpreted, creating a risk for miscommunication and potential accidents. Using radios allows for clear, direct communication that transcends visibility issues and environmental noise, enhancing overall safety on the job site.

While inclement weather, operations during night shifts, and the presence of a new operator might pose additional challenges, they do not inherently necessitate the use of radios in the same critical way as loss of visual contact or excessive noise. In fact, while visibility and comprehension may be compromised in poor weather or darkness, the most pressing concern remains the ability to communicate essential instructions when direct visual signaling is not feasible.