Raised pavement markers (road reflectors)

How to read it

The MUTCD requires a raised pavement marker to match the colour, by day and night, of the marking it guides, supplements or replaces: white or yellow. It allows the side seen by traffic going the wrong direction to be red, and uses red markers for truck escape ramps and for roads, ramps or lanes not to be entered from the direction they are seen. Retroreflective or internally illuminated markers can stand beside painted lines, supplement them or replace them in a pattern that copies the line. Illuminated markers burn steadily and are not flashed. California's handbook says that at night, a driver going the wrong way will see the road reflectors shine red.

Also searched as: blue reflectors on road, botts dots, cat eyes road, road reflectors.

Blue markers and fire hydrants

The 2009 MUTCD noted that blue raised pavement markers are sometimes used in the roadway to help emergency personnel find fire hydrants. The 11th edition (2023) drops that note; the only blue it gives for markings is on parking spaces for people with disabilities. Blue hydrant markers are set by state and local practice: Florida DOT's Standard Plans for raised pavement markers include a drawing of blue marker placement at fire hydrants, on two-lane and multilane roads and at intersections.

Spacing and patterns

The MUTCD measures marker spacing in units of N, one line segment plus one gap of the road's broken lines. Markers replacing a broken line come in groups of three to five, placed where the painted segment would be. Non-retroreflective markers are not used alone in place of other markings: a guidance in the 2009 edition, a standard in 2023.

Look-alikes

A red face seen at night and a WRONG WAY sign give the same message. Markers along a double yellow line are yellow; along a lane line, white.