Script SC40 Alternative path (by adlet)

This script allows to select alternative routes to destination, including setting cascades of alternative paths.
It also allows to replace stop selection signals, e.g. for more complex platform selection operations.

• Key features:

° Cascades of any length: marker M1 to M2, M2 to M3, etc.
° Set one or several destinations (e.g. station main and secondary tracks)
° Destination can be stop platform or any track
° Set time of day and days of week (weekdays, weekend)
° Redirect if set markers are reserved/occupied (can limit reserving trains to specific lines or tag)
° Limit re-direct effect to trains on specific lines or tag
° Disallow re-direct for trains with specific tags (e.g. line service tag overrides parent’s line tag)
° Tags are checked for line, train, schedule and shift
° Activate in one or both directions
° Re-direct signal can aggregate multiple marker actions

• Use cases:

° Replace waypoints
° Three or four track main line – select preferred track. Choose by time period or if trigger markers are reserved/occupied
° Stations/depots with platforms not accessible from every approach
For example, Philadelphia’s Center City Trolley Tunnel can function as in real life with this script.
° Direct train via alternative tracks in station throat
° Replace stop selection signals with custom re-direct instructions

• IMPORTANT: Not compatible with stop selection signals.

° Stop selection signal will override and trump script instructions.
° Stop selection signal opens/closes to train based on line stop settings (not on re-direct destination).

• Working layout, with comments, included with the download – see the mod folder (turn on user labels)

• How it works:

° Set a signal (marker, balise, path signal) which will redirect the train
Indicate the new destination (another marker, balise or path signal)
This can be a marker on a permitted platform for the next stop.
Multiple destinations are possible (will be selected by a path signal)
Redirect can be conditional (tag, day, time or marker reservation)

° To set multiple conditions on path signal, use 402 Path aggregator.
Place several markers with re-direct instructions (e.g. off-track).
Link them to the path aggregator signal.
Aggregator stops at first instruction where conditions are met.
For marker mode/signal direction, aggregator values are used.

° For multiple conditions not on path signal, can place several markers.

• Deployment notes:

° Presumes best-practice NIMBY signaling (see signaling guide). May not work properly with non-standard signaling",
° If destination is on scheduled station stop, train will stop. Ensure marker is set as the main or a secondary platform for the line. Destination marker can be used to set next destination (creates a cascade of markers).
° If marker is on platform, re-direct occurs 8s before the stop ends. Otherwise (marker not on platform), immediate redirect when passing.
° To change the standard marker setting, change Marker mode to Passthrough or WaypointStop, e.g. if marker is on platform after stop area, use Passthrough.
° Except with tag is useful to override parent line tag for a line service (eg a line with Applies with tag, but not line service with Except for tag.

° Do NOT use on a double stop, the train will skip the second stop.

° For multiple destination markers, place directing marker good distance before signal. Move if you see odd behavior.",
° Ensure marker arrows align with train direction; especially on single track lines, so marker does not affect opposite direction train.
° Destination marker does not need a script, unless also redirecting.
° Main platform stops do not need re-direct if there are no stop selection signals.
° To re-direct multiple line tags, or for multiple periods during the day, set up multiple markers. Remember each next marker will override the previous destination, if they both apply to the same train. Alternatively, use aggregator.
° The script does not protect single track lines. Use other scripts or normal NIMBY signaling for this (as in the example layout).

Additional information in the script guide within the game.

KNOWN ISSUES:

At maximum simulation speed, it is possible markers may not detect train direction. Please let me know. It’s a matter of calibration, and it’s possible the existing settings may fail in some circumstances.

The script will NOT work properly on a platform where trains have two or more stops: the train will depart after the initial stop and come back after the re-directs end. This is a game API limitation at the moment.

When a redirected train approaches a stop selection signal, it will pass or stop based on destination decided by stop selection signal, regardless of prior redirect destination. It will then be redirected to that new destination by the stop selection signal.