reading the signal…
Signals / Object / Street-level imagery
in Burlington, VT·counted·109 all time
A covered access opening to underground utilities, typically marked by a round metal lid in pavement.
Counted, not streamed: Manhole has no time series, so it is read as a footprint across places. All-time count by city.
Things that physically exist: street furniture, signs, buildings. All-time counts.