Some time at night it happens that we have to park our vehicle at highway because of some emergency and it may possible another speeding vehicle rams into another vehicle parked at the edge of highway. Mostly cars have flashing indicator, but heavy vehicle like trucks, buses and auto rickshaws have no such kind of indicator or warning flasher present. Here we have described a simple fleshing circuit which will be visible from a distance and warn the vehicle driver. This simple circuit is based on NE555 timer. In this circuit 555 timer is working in a-stable mode.In this mode 555 timer work as free running oscillator means it does not have any permanent or steady state and it is continuously changing its state from low to high and come back to its original state. This continuous switching from one state to another state from high to low and low to high produces a continuous square wave at output.