Abstract: A portable traffic warning device identifies hazardous traffic conditions at highway construction sites. The device includes an air hose that actuates a monitor switch whenever a vehicle travels over the air hose. A siren is operably coupled to the monitor switch and is capable of generating a high decibel audible alarm. A portable controller is coupled between the siren and the monitor switch and selectively couples power for preprogrammed amounts of time to the siren after the monitor switch is activated. A spool of retractable wire connects the monitor switch to the controller and allows the air hose to be placed at variable distances from the siren. A portable telescoping pole assembly is used for supporting the siren at variable vertical distances above the ground.