Guide

Roads, rail, subway, docks and airports

Last updated 13 October 2026

Traffic in Blockline is a city-wide balance between trips and capacity. Every mode you add either carries more cars or takes cars off the road.

How traffic works

Every day the city's workers and households make a number of trips. Some are walked, some go by public transport, and the rest are driven. The Services app on the Mayor's Computer shows the split as the city's mode share (walk, transit, drive), next to the average commute and congestion.

• Walking depends on walkability: compact districts with homes, shops and services close together walk more.
• Transit comes from bus stops, train stations and subway stations that are actually wired into a working network.
• Driving is everything else, and it is what fills the roads.

Congestion compares the driven trips with the city's total road capacity. As it rises, commutes lengthen, roads get noisier and land value along busy streets falls. Transport funding matters here too: neglected roads carry less traffic.

Roads

A plain road is cheap, carries every utility's mains and can run beneath existing power lines. An avenue is a dual carriageway with a planted median; paint it over an existing road to widen it in place, paying only the difference. It is a little noisier for the homes alongside.

A highway is a two-tile-wide motorway laid with a 2×2 brush, each tile carrying 3× a road's traffic, so a full cross-section carries 6× a road. Roads join it wherever they touch it, like an on-ramp, but it has no driveways: lots beside it still need a street of their own. It also can't cross a street (“Highways cannot cross streets: end the highway beside the road and it joins there”), and it is loud for the homes along it. Use it as a bypass between districts rather than a high street.

Bridges carry roads and power lines over water. A toll booth gates a stretch of road and charges the traffic passing through.

Bus stops

A bus stop is the cheapest transit: a kerbside stop that must face a street. Homes within 5 tiles take the bus, and each stop can carry up to 140 trips a day off the roads. It also lifts land value by 3 within 3 tiles.

Buses feed the commute but never replace a real network: they win at most 4% of the city's trips, and only among homes within a walk of a stop. Spread stops through residential streets rather than lining them up on one road.

Railways

Train track joins train stations into a line; you need at least two stations linked by track before anything runs. Trains then run the whole line end to end, and round loops, stopping at each station. Each connected station carries a fixed number of riders a day, which takes a real bite out of driving.

Level crossings

There is no separate crossing tool. Draw track square-on across a straight road, or a road across straight track, and you get a level crossing with barriers that come down while trains pass. It costs $60 more than the track or road that makes it, plus $0.15 a day for the signals. The rules are strict:

• Rail can only cross a straight road, not a junction or corner.
• Roads and rail must meet a level crossing square-on, not from the side.
• Rail crosses plain roads only: an avenue is too wide for a level crossing.
• Rail and highways never cross at grade: route one around the other.
• Level crossings need a clear tile between them.

Every crossing takes a little off the city's road capacity while traffic waits at the barriers, and the bells bother the homes right beside it. A few crossings are harmless; a line that crosses every street of a busy grid adds up. Bulldozing a crossing lifts the rail and keeps the road.

Railway bridges

A railway bridge carries track over rivers, lakes and sea inlets on a steel truss. Drag it along the water between two stretches of track, or simply drag train track across the water and the bridge is built for you.

The subway

A subway station is a surface entrance; the subway tunnel tunnels between stations are bored from the underground view (press U). Tunnels run beneath anything, so the subway is the way to add transit to a dense centre without bulldozing. A connected subway station carries more riders than a train station, at a higher price and upkeep.

The charter Connected to the world asks for a transit mode share of 5%. Two linked train stations or a pair of subway stations is the start; how far that gets you depends on how many trips the city makes.

Freight: docks and airports

Freight moves by road, rail, sea and air, and it limits how fast deliveries go out and how quickly construction crews get their materials. Each road tile carries a little freight; terminals carry much more:

A dock is a four-tile harbour berth that must sit on the open coast so ships can come and go. A shipyard beside it expands its cargo capacity, and several can be joined side by side. The airport is a six-tile airfield for passengers and freight; press R while placing it to rotate the runway. Hangars expand an airport's freight capacity the way shipyards expand a dock.

Passenger links also help tourism. A hotel houses 25% of your attractions' visitors, 10% more with an airport and 5% more with a linked railway. A theme park's visitor traffic is halved with a train or subway station within 5 tiles.

Unlocking transport

In a guided city, transport arrives chapter by chapter: bus stop with More than houses, train station with A town that pays its way, dock with A town that pays its way, highway with A skyline of our own, subway station with Opportunity for everyone and airport with Connected to the world.

Tip. Fix congestion with capacity where the cars are and transit where the people are. Widening a central road to an avenue and adding bus stops through the suburbs usually beats a highway across town.

Roads and rail wear out like any network; see construction and maintenance.