Schools

[1ec5]

Even though this project is currently focused on the lower zoom levels with large features like roads, I think it’s time to start thinking about what we’d need for proper rendering of points of interest at higher zoom levels, because the tagging system for some points of interest may fit American cartographic needs even less well than for transportation features.

For sure, the style would at some zoom levels mark schools, which are important community institutions that serve as a point of reference for other places around town. The description below is focused on what a reasonable end result might look like, but it’s likely that we’d need to focus on coverage of certain tagging schemes to make the suggested treatments work.

Icon

Conventionally, street- and community-level maps of the U.S. depict schools as pitch-roofed buildings with a pennant-shaped flag on top.

Typically, community institutions (such as schools, post offices, hospitals, and police and fire departments) are marked by only a simple icon at middle zoom levels where there wouldn’t be enough room for a full label. However, some maps pack a bit more information in school icons:

• Some place a small letter inside the building to indicate the school’s classification – typically “E” for elementary, “M” for middle school, and “H” for high school, but other initials are possible.
• Some highlight middle and high schools with a darker fill than elementary schools to emphasize the relative size and importance.
• Some place more than one flag on the roof to flag an institution of higher education.
• Some replace the pennant with a religious symbol such as a cross for religious schools. (The color or letter distinguishes the religious school icon from the church icon.)

(Some maps in my collection use the flag-on-house symbol for a fairgrounds, and some use a filled square for educational institutions, but those seem to be in the minority.)

Label

I recall seeing some maps that use the label instead of the icon to indicate a school’s classification. For example, it might say “(Grades 1–8)” in fine print beneath the school name.

Fill

Many maps fill school buildings in a darker or more brilliant color than other buildings, to give them more prominence.

Some maps also fill schoolgrounds, particularly the ones that are at a high enough scale that they don’t need to show an icon.

[1ec5]

Some place a small letter inside the building to indicate the school’s classification – typically “E” for elementary, “M” for middle school, and “H” for high school, but other initials are possible.

There are a few ways to approach this problem, each of them with caveats:

• The school can be tagged school=primary/elementary/etc. and OpenMapTiles could expose the school value to the stylesheet. This is straightforward, but the set of allowable values for U.S. schools would need to be determined. It might also be difficult to convince OpenMapTiles to add support for a tag that grew so organically.
• OpenMapTiles can expose the grades=* value to the stylesheet, which would classify the school based on the grade span according to hard-coded thresholds. This may be messy, because terms like “intermediate” and “elementary” are relative to other schools in the same district; they aren’t standardized at the state or national level.
• Some mappers prefer isced:level=* for international consistency, but in the U.S., an ISCED level on its own is almost meaningless. There’s also a significant difference between how ISCED 2007 and 2011 map to the U.S. educational system, which means existing tags can’t necessarily be trusted.
• The stylesheet could look for some expected substrings like “High School” in the name using the index-of operator. However, this approach is fragile like anything that requires parsing freeform text. In particular, many elementary schools aren’t named as such but are understood to be elementary schools based on their grades and in the context of the other schools that are part of the same district.

[1ec5]

Some mappers prefer isced:level=* for international consistency, but in the U.S., an ISCED level on its own is almost meaningless. There’s also a significant difference between how ISCED 2007 and 2011 map to the U.S. educational system, which means existing tags can’t necessarily be trusted.

I expanded on this point in a diary entry.