Public service safety vests, also known as ANSI 207-2006 vests, are high visibility vests, intended for law enforcement, fire and emergency responders. The vests are designed to meet the visibility standards of ANSI 207-2006. Typically worn by police, fire fighters and emergency medical services (EMS) personell, ANSI 207-2006 vests are designed to protect first responders from roadside traffic, by making them more visible even in inclement weather or at night.
In addition to the added visiblility, a public service safety vest has the added feature of being a "breakaway" vest, meaning that the front, back and sides of the vest are attached with velcro, making it easy to tear off should the vest get caught on an object. Public service vests are also shorter in length than a regular safety vest, and have cut-out sides for police weapons or EMS equipment.
A great selection of public safety vests, as well as other ANSI reflective vests can be found at http://www.mysafetywear.com/.