Gibson Biddle advocates a rolling roadmap that always covers four quarters: the near-term quarter(s) carry high-confidence, largely committed projects, while the out-quarters are explicitly provisional and expected to change as the team learns. Rather than a fixed annual plan, the roadmap rolls forward each quarter, re-deriving the far-out contents from what's been learned in the near term. This keeps a Roadmap (Feature/Project List) honest about uncertainty without abandoning near-term commitments — related to Commit to Time Frames, Not Fixed Dates but framed at the portfolio/quarterly-cadence level rather than the single-commitment level.