Use of Warning Lights and Siren in Emergency Medical Vehicle Response and Patient Transport

The use of warning lights and siren (L&S) by prehospital emergency medical services (EMS) vehicles is a basic component of emergency response and patient transport. This public-safety practice predates modern EMS by 50 years. Despite the long-term reliance on L&S, it is not a risk-free practice. There are many reports of emergency medical vehicle (EMV) collisions during L&S responses and transports. These collisions often result in tragic consequences for the EMV occupants and those in other vehicles, and may cause significant delays to medical care for the patient the EMV was responding to or transporting. While there is no systematic collection of EMV collision data, some authors have suggested that the available information underestimates the extent of the problem. In addition, to date there have been few published analyses regarding the effectiveness of L&S as a modality that improves response times or, more important, patient outcome.