Roundabout

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Railway Junctions
Junction Criteria

3-Way junctions

Basic 3-Way
Line Merge
Half Cloverleaf
Half Spaghetti
Compact 3-Way
Compact 3-Way B-M Junction
Ultimate 3-way
Half Transmogrified
Braided Junction

4-Way junctions

Basic 4-Way
Roundabout
Cloverleaf
Spaghetti
Star
Complex Star
Branch-Merge
Over-Under
Tetrathorp
High Speed 4-Way Fly-over/under
Pre-Signaled Roundabout
Advanced Roundabout
Right-of-way Roundabout
Improved Roundabout
Transmogrified
Tightlong
Deepblue2k8 4-way Junction

Enormous junctions

Multi-way/multi-track cloverleaves
Dual Tetrathorp
Dual Transmogrified
Dual Branch-Merge
Quad Branch-Merge
Quad Tetrathorp
6-tuple Branch-Merge
8-Way Star
High Speed 4-way

Other junctions

Right-of-way Depot
Dual tunnels
Sideline U Turn
Right-of-way Lane Change
Right-of-way Merge

Track Layouts

4-Way Triple Axial
4-Way Triple Axial 2
Triple Via Mini
High Hill

Unuseful junctions

Crossover
3/4ths junction
Ultimate 3-way junction for 4 tracks

The Roundabout consists of a circular route one-way with different entrances and exits.

Roundabout junction


Junction Criteria
CostCheap
Construction DifficultyEasy
TunnelsNo
BridgesNo
Breakdowns
Broken down trains affect two segments up to the whole junction.
Sharpest Turn1.5
HillsNo
Direct PathsNo
Natural TurnsNo
DeadlockYes
LoopsYes
  • Can handle up to 2 trains at a time
  • When you make it bigger, you can create a 8-way roundabout
  • Will cause traffic jams.
  • Area: 6 x 6


Contents

Roundabout with path based signals (PBS)

Constructing a roundabout with PBS at its entries allows multiple trains to use the junction. Since there are no signals within the loop, deadlocks become impossible.

Roundabout with path signal entries.

The goods train [A] passes the junction from the upper right to the lower left corner (1 to 3). This does neither affect the passenger train [B] (3 to 4) nor the cattle train [C] (4 to 1).


Junction Criteria
CostCheap
Construction DifficultyEasy
TunnelsNo
BridgesNo
Breakdowns
Broken down trains affect one direction up to all but one directions.
Sharpest Turn1.5
HillsNo
Direct PathsNo
Natural TurnsNo
DeadlockNo
Signal type PBS
  • Low cost, low space consumption and relatively high efficiency


Roundabout with PBS and bridges

This slight modification allows crossing trains not to interfere with each other.

Roundabout pathsignals bridges.png

Without bridges, both the grain [A] and steel train [B] would go through the roundabout, causing one of both trains to wait for the other one to pass by. The additional paths for trains just going straight ahead increase the roundabout's efficiency even more, without need of additional space!

Junction Criteria
CostCheap
Construction DifficultyEasy
TunnelsNo
BridgesYes
Breakdowns
Broken down trains affect one direction up to all but one directions.
Sharpest Turn1.5
HillsNo
Direct PathsNo
Natural TurnsNo
DeadlockNo
Signal type PBS


Variations

  • When you make it bigger, you can create an 8-way roundabout.
The same, but 8-way, roundabout concept.

Split Roundabout

This modification allows trains to pass faster.

Roundabout junction


Junction Criteria
CostCheap
Construction DifficultyEasy
TunnelsNo
BridgesNo
Breakdowns
Broken down trains affect whole junction.
Sharpest Turn3.5
HillsNo
Direct PathsNo
Natural TurnsNo
DeadlockYes
LoopsYes
  • Can handle up to 7-8 trains at a time
  • Low possibility to cause traffic jams if there are less than 8 trains.
  • Area: 33 x 33
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