Plastic Road Studs. BASIC INFO Package. Plastic road studs, or called plastic raised pavement markers, are important road safety devices which can enhances their visibility by retroreflecting automotive headlights to guide the road direction in dark light situation. In some countries, they are used as speed breakers in gas station, school and urban street etc. Roadsky is professional manufacturer of raised pavement markers which can provide customized plastic road studs for different demands.