FA-68038 / Traffic signal timing plans / Member archive

Coordinated local cycle timer: only the yellow is subtracted from the split to find green end · case 03

Coordinated local cycle timer returns a wrong result when only the yellow is subtracted from the split to find green end.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Input {cycle, offset, master, splits: [[phase, split s]] in sequence starting with the coordinated phase, yellow, red, ref}. Splits must sum to the cycle, else 'bad-splits'. Local time = (master - offset) mod cycle, where the offset marks the start of coordinated green (ref 'begin') or the end of coordinated green (ref 'end'). Each split is green then yellow then all-red. Return [phase, interval, seconds remaining].

Why this case matters

Signal timing arithmetic is exact and integer or rational; a wrong rule silently produces unsafe or inefficient timing plans.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
timing oracle 2	`[4, "green", 19]`	`[4, "green", 17]`	Failed

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