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Road Networks and Segregation

The single most important skill in Mini Motorways is managing traffic flow. A unified grid where every road connects to every other road is a guaranteed path to failure. To survive into the late game, you must learn color segregation and intersection management.

Color Segregation​

Your primary goal is to isolate traffic by color. Do not allow red cars to drive on the same road as blue cars if you can avoid it.

  1. Dedicated Paths: Draw a direct road from a cluster of red houses to a red destination.
  2. Avoid Shared Arteries: If you funnel multiple colors onto a single "main street," cars will slow down as they interact with each other. This creates severe congestion.
  3. Bridge and Tunnel Usage: Use bridges and tunnels to cross over geographical obstacles, but do not use them to merge different colors unless absolutely necessary.

When you segregate colors, cars travel at their maximum speed because they never have to yield to crossing traffic.

Minimizing Intersections​

Every intersection forces cars to slow down and check for cross traffic.

  • Y-Forks over T-Junctions: While a three-way T-junction prevents the hard stops of a four-way cross-road, the engine dictates that vehicles still decelerate heavily at 90-degree turns. By manipulating the eight-way directional grid, you can merge two roads at a 45-degree angle (a "Y-fork"). This acute angle merging minimizes the internal deceleration penalty, allowing traffic to maintain higher velocity.
  • Angle of Approach: Cars slow down more for sharp turns. Try to make intersections as smooth as possible by angling the approach roads.
  • Driveway Placement: The driveway of a house is an intersection. Do not connect house driveways directly onto your main high-speed roads. Instead, group a cluster of houses onto a local "neighborhood" street, then connect that single street to the main road.

The "One to One" Rule​

In the early game, try to achieve a strict one-to-one ratio: one cluster of houses connects to exactly one destination, with zero outside connections.

As the city grows, this becomes impossible. When you must share roads, group compatible demand. If you have two red destinations near each other, it is safer to share their traffic than to mix red and blue traffic.

Pathfinding AI and Pin Reservation​

To design effective networks, you must understand how vehicles select their routes and when they depart.

  • Unweighted Shortest-Path: The pathfinding AI is entirely oblivious to traffic density. It uses a strict, unweighted shortest-path algorithm (tile counting). If you build a 21-tile bypass to relieve a congested 20-tile road, 100% of the cars will still choose the 20-tile road. Bypasses only work if they are mathematically shorter in total tile distance than the original route.
  • Pin Reservation: A commercial destination generates a "pin" representing demand. A car only leaves its driveway if a pin is actively available. The exact moment the car departs, it virtually reserves that pin. If a car must travel a massive physical distance, that pin remains reserved for the entire journey, artificially inflating the destination's visible backlog and triggering the game-over timer.

Destination Demand Scaling​

Connecting too many houses to a single building causes catastrophic intersection congestion. You must scale your housing connections based on the destination's geometry:

  • Square Destinations: These are low-demand entities. Early on, 1 to 2 residential houses fully service a square building. Post-1,000 trips, internal algorithms scale up, requiring 6 to 7 houses to meet the accelerated pin generation.
  • Circular Destinations: These are high-demand entities. Early game survival requires 3 to 4 houses. By the late game, you must connect 12 to 15 houses to a single circular building to prevent a game-over.
  • Double-Parking Lots: High-demand destinations occasionally spawn with two separate parking lot entrances. Do not merge traffic at the entrance. Feed these entities with two entirely segregated, disjointed road networks to halve traffic density right at the point of delivery.

Redesigning Your Network​

Do not be afraid to hit pause and delete large sections of your network. The game does not penalize you for redesigning.

If you notice a traffic jam forming, pause immediately. Trace the route of the cars and look for unnecessary intersections. Often, pulling one color off the shared road and giving them a dedicated motorway solves the problem instantly.