The ornamental design for a safetymarkingstrips, as shown and described.
FIG. 1 is a first perspective view of safety marking strips embodying my new design;
FIG. 2 is a second perspective view of safety marking strips of FIG. 1;
FIG. 3 is a front view of the safety marking strips of FIG. 1;
FIG. 4 is a back view of the safety marking strips of FIG. 1;
FIG. 5 is a side view of the safety marking strips of FIG. 1;
FIG. 6 is a top view of the safety marking strips of FIG. 1;
FIG. 7 is a bottom view of the safety marking strips of FIG. 1; and,
FIG. 8 is a third perspective view of the safety marking strips of FIG. 1 that illustrates an example environmental structure of the safety marking strips on a baby carriage.