City of Detroit, you rock. I decided to finish my presentation of the stamps I saw in the Fox Theatre by checking on Detroit’s sidewalk stamp rules. I could tell that they must require them, since they were thick on the ground there, even compared with Lansing. Lansing may have earned my respect by codifying sidewalk stamps, but Detroit’s sidewalk stamp ordinance is on another level:

The Contractor’s name and the year in which the walk or drive was laid shall be carefully and clearly impressed in the concrete surface of each isolated flag, each flag at the property line, and in each end flag or slab of two or more adjoining flags or slabs. Each individual flag adjacent to a tree, whether arced or not, shall be also marked, as directed by the Engineer.

The stamp or plate used for marking shall have an approximate maximum dimension 100 mm x 150mm (4 x 6 inches), outside dimension. The Contractor’s name and the current year’s date shall be in such characters and arrangement that legible and indelible impression may be made in the concrete.

The work will be considered incidental to the cost of construction.

Sec. 12.III.12: “Contractor’s Stamp,” Standard Specifications for Paving and Related Construction, City of Detroit Department of Public Works, March 2009

The very detailed and strict set of rules mostly speaks for itself, but two points stand out. One is that it requires stamping not just at the start and end of a run of sidewalk but at the property line and, curiously, adjacent to each tree. The other is the last line, “The work will be considered incidental to the cost of construction.” I assume that means “Don’t try to charge extra for installing stamps” and it makes me wonder if there were incidents that resulted in adding that clause.