It's really just a list, a rather simple list — albeit with Burtonian overtones (I've had a melancholy few days here) — and surely an incomplete one as well. You can skip it if it's just too dumb — but then you can do that with any of these posts, can't you?
OK, enough apologies. Here goes: What changes?
The island itself
The shoreline, which gets extended by landfills and piers and jetties (though the latter are less often thought of as shoreline extensions and, technically, possibly even legally, I suppose they are not) and sometimes gets pulled back, when piers or jetties are dismantled or even, sometimes, when landfill is (re)excavated. — All of these different kinds of shoreline changes seem to have happened to one extent or another west of Tenth Avenue below 23rd Street since the street plan was first proposed 200+ years ago, and have certainly happened, extensively, elsewhere on the island, especially downtown, of course.
The terrain gets levelled, hills cut down, valleys filled. — This too has happened along the lower stretch of Tenth Avenue, and the upper stretches too, and throughout the island as well.
The street plan and the streets themselves
New streets are laid out, for instance in Battery Park City and Trump Place in recent years, and existing streets are sometimes closed, particularly to create the "superblocks" that were, and are, characteristic of the big "urban renewal" housing projects; streets are also sometimes just partially closed, e.g., closed to regular traffic, but open to service and emergency vehicles, bicycles, and pedestrians. (I'm not going to include temporary closings for repairs or in connection with construction projects.) — Tenth Avenue below 23rd Street, as already mentioned, and of course the streets west of it, are a prime examples of street plan changes in the area we've been looking at.
Other transportation infrastructure
Bridges and tunnels are built, along with their entrances and exits, and sometimes closed too. Bus depots — just below 42nd Street, Tenth Avenue catches a number of the ramps leading to the Port Authority Bus Terminal. And railroads and their stations: elevated, at street level, subways. And also railroad yards and maintenance facilities. — Both in evidence on Tenth Avenue: the old New York Central yards west of the avenue between 30th Street and 33rd Street; the subway yards and maintenance depot east of the avenue way uptown in Inwood.
Oh yes: heliports and ferry terminals.
Sidewalks, curbs, wheelchair ramps, paving materials for both streets and sidewalks, the delineation of crosswalks and vehicle lanes (both in general as well as special lanes for buses), parking. And designations of traffic as one way or two way.
And not to forget all the different, and changing, kinds of traffic itself: pedestrian, vehicular; cars, trucks, buses, emergency vehicles, but earlier in the city's history trolleys, horses, carriages …. (And yes, I did almost forget: this paragraph is a late insert, in the middle of proofreading the others.)
And also not to forget traffic signage: street name signs, one way and two way traffic signs, other traffic management signs (stop, do not enter, no commercial vehicles, no parking, no standing); traffic lights, informational and directional signs (West Side Highway this way); bus stop markers, bus schedules and routes, subway signs, line and entrance markers.
Other infrastructure, n.e.c. ("not elsewhere classified")
And a whole host of other infrastructure visible on the street, or having visible access from the street: manholes and their covers, sewer grates, fire hydrants, sub-sidewalk ventilation grids, street lights, trash cans, surveillance cameras.
To say nothing of trees, planters, gardens, mini-parks, little bits of lawn, "weeds."
And the odd bits of street furniture: those colorful plastic boxes for the free newspapers, ads, and so on. And at the other extreme of size: billboards and their support structures (not counting the more recent large scale ads on canvas hung from the sides of buildings that are made possible by the technology of inkjet printing on wide-carriage printers).
Or does this category belong under changes to the island itself? Well, somewhere in between, perhaps. In any event, trees, lawns, gardens, plantings, roads, walks, paths, ponds, streams, pools, special facilities like toilets, snack bars, restaurants, zoos, outdoor theaters, boat sheds ….
Which get built, demolished, renovated, get facelifts, new paint, tuckpointing and other clean-ups, new window frames, awnings, canopies, doors, window treatments.
Businesses, residents, new or not to the neighborhood, the city, time (no cellphone stores opening in the 1870s). Storefronts are vacated, new tenants move in, the same business or a different business, new owners, same owners, new or different management.
And the related property signage: ID signs for businesses, but also for sale, for rent, property owner or manager.
And all the stuff of construction: fencing, plywood or chain link, scaffolding, safety netting, cranes both tower and portable, temporary elevators, concrete, plumbing, electrical, glass, and other supplies and related installation equipment.
Worthy of a whole study in itself (I mean a sociological study) — surely someone has done it? Trash cans, litter, paper trash including bundled magazines, newspapers, books; also recyclables, but also discarded furnishings, rugs, chairs, sofas, chests of drawers, beds, mattresses, tables, lamps, appliances, decorations (posters, prints, paintings, photos — I once bought one of my own paintings from a street vendor who had retrieved it from the trash where I thought it belonged — paid too much for it too), clothing of all kinds, bedding, pots and pans, dishes, cutlery, mirrors, garbage in the sense of discarded food, bottles — the list seems endless.
But this is a whole post unto itself, and no doubt more than one, many more than one.
As is this one, the changes in what one sees depending on time of day: it's a very different city early in the morning, in the AM rush hour, at midday, in the PM rush hour, in the evening, the late evening, the wee hours.
To say nothing of the seasons — and the weather: rain, sun, snow, hot, cold: you don't see them, but you see their signs: overcoats, shorts, steamy breath, umbrellas ….
— OK, yes, trivial, everybody knows this, whether they know it or not. But — and this is the impossible assertion — all this and more is constitutive of the visual experience of the city, and in many ways, directly and indirectly, all these things, which are things that, like all things, either change or don't, or, to be more precise, change at different rates and at different times, with different degrees of consequence for everything else (also changing …).
Sometimes, for me at least, lists like this are helpful, not as "checklists" per se — is everything really covered? no, of course not, why else all those "and not to forget's?" — but on the one hand to begin to take the measure of a problem, and on the other to jostle the mind just by bringing so much to the foreground or surface, if only for a moment, in a simple list.