The new substance, which is invisible by day but reflects cars’ lights at night, increases the visibility range of people wearing dark clothing from about 40 meters to around 150 meters, local police said.

The new project was launched on the night of Halloween in the Łódzkie province and will involve otherwise hard-to-see pedestrians sprayed at accident blackspots where visibility is particularly poor.

“We have not used such a solution before because it’s a new method that makes pedestrians or cyclists visible on the road and therefore safer,” a local police spokesperson told the Fakt daily.

She added that the spray is colorless, does not stain clothing, and can be applied to jackets, bags, shoes, bikes or backpacks so that motorists will see them.

The spray will only be used on people with their consent and volunteers will be able to choose which items are sprayed.

Local police said several locations had been identified for use of the spray and that it would start being used at the railway station in the village of Gorzędów, where there is no street lighting and the sidewalk is still under construction.