1. PCC. Portland Cement Concrete. Commonly called a 'concrete surface.' This also has a control joint running through the picture...tricky.

2. Hotel sidewalk. Many hotels sport a red carpet like this one.

3. Plate. Giant steel plates used during construction and maintenance present occasional problems due to sharp edges and low friction.

4. Patch. Notice the difference in color between the two sections.

5. Light rail.

6. Crosswalk. This is the ragged and used white line of a crosswalk. Still slippery when wet.

7. Asphalt cement concrete. This common street surface is also a type of concrete, although very different from PCC.

8. Joint. You can't smoke a joint like this one, but it will smoke you if you're not careful.

9. Map crazing. Also called alligator cracking, alligator crazing, map cracking and very rarely crazy alligatoring.

10. Plaza. Slippy as ice when wet. Not your normal patio.

11. Grate.

12. Alley. By process of elimination.