How to Fix Traffic in Cities: Skylines, Step by Step
by Bouse-Town Team8 min read
Fix Cities: Skylines traffic in this order: read the traffic info view, reduce the number of vehicles, give every road a job in a clear hierarchy, cut unnecessary intersections, and check where lanes merge. Widen a road only after you identify the specific bottleneck; extra lanes do not repair a network that still funnels every trip through one junction.
Cities: Skylines is the city builder from Colossal Order, published by Paradox Interactive, and its traffic simulation punishes one mistake more than any other: asking every trip to use the same road. The game's own official wiki Traffic page frames the problem in terms of flow, distribution, and demand, which is the right vocabulary for fixing it.
Filed from the town dispatch, where the only queue we manage is the one at the food barrel.
Start with the traffic info view, not the wrecking ball
The traffic info view paints your road network green and red by how heavily each road is used. A red road is information, not a verdict. The wiki's own note on info views is worth repeating: a red road is heavily used, and it is not always clogged.
Before you demolish anything, answer three questions:
- Is the congestion one intersection or a whole corridor?
- Are the vehicles mostly citizens, tourists, or freight?
- Is the jam at a city entrance, a district boundary, or a single building?
That diagnosis decides the fix. A single intersection jam needs intersection work. A corridor that is red for a mile needs fewer intersections or an alternative route. A city entrance that is always red needs distributed access, which is a demand problem, not a paint problem.
The fix order that actually works
The fixes below build on each other. Follow the order and you solve most cities without ever touching a mod:
- Cut vehicle demand. Add buses, metro, and cargo rail so fewer trips need a car or a truck.
- Build a road hierarchy. Highways feed arterials, arterials feed collectors, collectors feed local streets.
- Remove intersections. The wiki's beginner guide is blunt: fewer intersections is better, and traffic lights disturb flow.
- Test roundabouts at busy intersections. A well-sized roundabout can remove traffic-light stops, but poor spacing or lane changes can move the queue instead of solving it.
- Match lane counts. Keep the lanes entering and leaving an intersection consistent so no lane bottlenecks into a merge.
Widen only after steps one through five, and only on the specific road the info view keeps red.
Road hierarchy: give every road a job
Every road type in Cities: Skylines does one job well and several jobs badly. A two-lane street that carries a highway's worth of traffic fails because it was never meant to. Use the hierarchy the community has refined for a decade:
| Road type | Job | Design rule |
|---|---|---|
| Highway | Move vehicles fast across long distances | Few exits, wide spacing between interchanges |
| Arterial | Carry traffic between districts | 4 to 6 lanes, few intersections, no parking-heavy zoning |
| Collector | Gather traffic inside a district | 2 to 4 lanes, connects arterials to local streets |
| Local | Serve buildings | 2 lanes, dead ends and loops welcome, slow speeds |
The classic failure is a local road connected directly to a highway exit. Every trip in that neighborhood then shares one low-capacity road with every truck, bus, and commuter, and the result is the exact red blob you are looking at. Route the exit into an arterial first, then let the arterial distribute traffic.
Roundabouts, and why size matters
Roundabouts are one useful intersection option. The wiki's Roads page notes that a roundabout avoids traffic lights and can reduce congestion by removing the stop-start at a junction.
Two details decide whether your roundabout helps or becomes a smaller traffic jam:
- Size matters. The beginner guide warns that small roundabouts force cars to slow down more, which hurts flow. Build them big enough for the turning radius to stay gentle.
- Lanes must continue. If the roundabout feeds into a two-lane road on one side and a six-lane road on the other, the merge becomes the new bottleneck. Match the approach lanes.
Use a roundabout where two busy roads cross. Keep the plain intersection with a light where the roads are quiet, because a roundabout where it is not needed still costs space and slows the network.
Move freight off the roads
Citizen traffic gets the headlines, but freight trucks are often the real cause of a red industrial district. The wiki's beginner guide recommends cargo rail in industrial districts because it develops the district and removes part of the traffic, and the Traffic page lists cargo train terminals and cargo harbors as the freight equivalent of public transport.
One warning from the same source: every train that arrives spawns a column of trucks that carry goods to their destinations. A cargo station needs its own good road access, ideally a collector or arterial that keeps the truck queue off the main corridor. Place the station near the industry it serves, not in the middle of a residential grid.
Public transport removes cars
The wiki's Traffic page states the strategy in one line: public transportation is an easy way to remove cars from the road. Buses, trams, and metro each replace private trips, and each trip removed is a vehicle that never enters the network.
Route transit along your arterial roads, not along local streets, and place stops where buildings actually generate trips: schools, commercial strips, and industrial gates. A bus line that crawls through the same congested corridor it is supposed to relieve just adds another vehicle to it. The Heavy Traffic Ban district policy also pushes through-traffic onto larger roads, which the Traffic page lists among the distribution tools.
Keep lane counts consistent
Lane mathematics sounds like a mod; it is actually a layout rule. Wherever lanes split or merge, keep the count on both sides of the intersection close to equal. A six-lane arterial that dumps into a two-lane collector guarantees a queue at the transition, because three lanes of traffic try to become one.
One-way roads help here. A pair of one-way streets can split a two-way corridor into clean directional flows, and the lane arrows at an intersection let you dedicate a lane to turning instead of letting every lane compete for the straight-through line.
If you play on PC and want finer control, the community mod Traffic Manager: President Edition (TM:PE) adds lane connectors, timed lights, and turn restrictions. It is a refinement layer, not a substitute for the fixes above; a mod cannot save a city with one entrance and no transit.
The honest part: Cities: Skylines II is a different simulation
Cities: Skylines II launched in October 2023, and Colossal Order changed the traffic model underneath it. The official traffic development diary explains that vehicles use more lanes and try to optimize road usage, and the road info view reports flow and volume per road rather than a single city-wide color.
The fix order still holds: cut demand, build hierarchy, remove unnecessary intersections. But the exact tools differ. There is no TM:PE equivalent at the same maturity, roundabouts behave a little differently, and the simulation is more sensitive to road design than the original. If you search for fixes, filter for Cities: Skylines II specifically, because a 2015-era lane trick does not always transfer.
What this has to do with Bouse-Town
Honest disclaimer first: Bouse-Town does not simulate traffic. It is a satirical camp-management game in development for the web and iOS, and the road network ends where the camp gates do. No cars, no lanes, no roundabout placement in your save.
What transfers is the discipline underneath this guide. Before you click anything in a management game, read the system: which resource is the bottleneck, what is competing for it, and which choice changes the next three moves. That is the same habit as reading the traffic info view before demolishing a neighborhood. Our strategy guide walks through reading consequences before you click, the seeded randomness dispatch explains why a saved state resolves consistently so reloading is not a strategy, and the construction report tracks what each upgrade actually costs.
When Bouse-Town eventually has queues, we promise they will be for the food barrel, and we will probably write a dispatch about those too. Until then, explore the camp the same way you read a red road: slowly, and with the ledger open.
Frequently asked questions
Why does my highway entrance always back up?
Check whether it is your only practical entrance. If most trips share it, distribute access and move demand off the road with transit or cargo rail. Then inspect the first downstream intersection, because that junction may be the real bottleneck.
Do I need mods to fix traffic?
No. Start with road hierarchy, intersection spacing, transit, freight access, and lane merges in the base game. On PC, TM:PE adds fine-grained control, but it cannot replace a network diagnosis.
Does this guide work for Cities: Skylines II?
The principles do: cut demand, build hierarchy, remove unnecessary intersections. The implementation differs because the sequel's vehicle pathfinding uses lanes and routes differently, so apply the ideas and verify each one against the current game version.