Guide
Reading the map: overlays and the underground view
Most of what decides a Blockline city's fate is invisible from above. The overlays and the underground view are how you see it.
Data overlays
Overlays tint the map with information you can't see from the buildings themselves: land value, and how far each service reaches. Press Shift+D on the map to step through them, or pick one from the overlay button on the map. A legend shows what the colours mean. Most Services rows on the Mayor's Computer also have a button that opens the map with the matching overlay switched on.
Desirability
The desirability overlay paints every tile on the 0 to 9 land value scale, from blighted reds to prime greens. It is the single most useful overlay: it shows where lots will grow, where they are about to decline, and which building is dragging a neighbourhood down. The desirability guide explains what moves it.
Service coverage
The other overlays show service reach. Each covered tile is shaded by strength: strongest beside the building, fading towards the edge of its reach, with the best building winning where several overlap. The table gives each building's standard reach in tiles.
| Overlay | What it shows | Fed by (reach in tiles) |
|---|---|---|
| Police | Streets within reach of a police station's patrols. | Police station: 12 |
| Fire | Tiles a fire station's crews can reach when fire or disaster strikes. | Fire station: 10 |
| Health | Homes within reach of a hospital or clinic. | Hospital: 14 Clinic: 8 |
| Education | Homes within reach of schools, libraries and universities. | School: 8 Library: 8 University: 12 |
| Transit | Tiles a short walk from a bus stop or station. | Bus stop: 5 Train station: 5 Subway station: 5 |
| Waste | Homes on a waste depot's collection rounds. | Waste depot: 10 |
| Digital | Tiles on a served internet network or within a cell tower's range. | Cell tower: 10 |
For the digital overlay, the cell tower is the only source with a radius; an internet exchange or data centre serves whatever its network's streets and fibre reach (see utility networks).
Reach isn't fixed. It depends on the department's funding: an unfunded department's buildings reach about 75% of their standard distance, and full funding at 150% stretches it to about 106%. The Police HQ and City Hospital extend the reach of the stations and hospitals they coordinate (see venues).
What coverage numbers mean
The Services app, the Problems app and the advisers all judge utilities by the same lines. At 90% coverage or more, a utility is healthy. Below that it becomes a warning, and below 70% it is critical.
Because coverage fades towards the edge of each building's reach, the far edge of a station's circle is only weakly served. Spread stations out so their strong centres sit among the homes, rather than stacking two in one place where their reach mostly overlaps.
Tip. When placing a new service building, switch to its overlay first. The gaps in the colour show exactly where the next one should go.
The underground view
Press U to switch to the underground view, and again to come back up. Below ground you can see and build water pipes, sewers, fibre and subway tunnels, all of which can run beneath streets and buildings without disturbing them.
The underground view also draws each utility network in its own colour, along with the sources that feed it and the buildings it serves. That makes it the place to diagnose a shortage: if a district is short of water while the city has plenty, you will usually find it on a separate network with no tower of its own, one pipe away from the main system.
Things to check underground
- Isolated networks: a cluster in a different colour from the rest of town.
- Plants and towers set back from the street with no conduit joining them up.
- Subway stations that aren't joined by tunnels; a station on its own carries nobody.
- Routes for new tunnels and sewers before you commit to a big surface build on top.
Other things the map tells you
Select any building to open its info card, which explains what it does and offers any actions it has. That is where you convert industry to clean energy and where you walk into the venues. The queue of building sites lives in the Construction app (see construction and maintenance).
The fastest way to work: check Problems on the Mayor's Computer to see what is wrong, then use an overlay or the underground view to see where.