(b) Any employee of the department who, on or after July 1, 1987, is injured in the line of duty by an act of external violence, accident, or injury shall be entitled to receive compensation as provided in this Code section. Going to and from work shall not be considered in the line of duty. For the purposes of this Code section, "line of duty" means working in the proximity of traffic movements or equipment movements doing maintenance, construction, or other activities which may be construed as hazardous.