11 May 2026

They Called It False Hope. We Call It a Fair Question.

This is one of the most consequential analytical challenges in the entire campaign. The following discussion sets out, with full source attribution, why the DfI position is analytically unsound and institutionally self-defeating. Whatever the next move, the truth shall be highlighted and the honest answer sought. Don’t underestimate persistence. Important post blog note worth reading.

STRANGFORD LOUGH CROSSING CAMPAIGN Analytical Discussion Note: The Static Demand Assumption and Its Evidential Failings Kevin Barry BSc(Hons) MRICS | strangfordloughcrossing.org | May 2026

1. What DfI Officials Have Actually Said: The Documentary Record

The campaign’s position must rest precisely on what DfI officials have placed on the record. The following statements are confirmed by retrieved primary documents.

Mark McPeak, Divisional Roads Manager, Southern Division, in his internal ministerial advice memorandum of 22 August 2024 (DfI reference COR-1578-2024, disclosed under FOI reference DFI-2024-0412) stated: “The traffic volumes currently using the Strangford Ferry Service would be insufficient to justify the major investment to construct a permanent crossing.”

In the same document, his payback calculation reads as follows: “The cost / benefit of accommodating on average 650 vehicles per day at a ferry charge (single car) fare of £7.70 (2024 fare) amounts to £5,000 per day. On this basis it would take 356 years to recoup costs.”

This calculation was cleared by David Porter, Head of Division, on 30 August 2024.

The Department’s formal institutional position, carried forward by Ian McClung, Head of Consultancy Services, in TOF-0467-2025 (24 October 2025), confirmed that the ferry “meets both current and projected demand” and that a feasibility study “would not be a good use of public funding.”

The Sian Kerr “Raising a Concern” investigation outcome (19 January 2026) found, on the McPeak methodology, that “advice was transparent about cost limitations” — explicitly acknowledging that the figures were characterised as “guesstimates” and a “very rough cost estimate” — but found no evidence of institutional resistance and closed the matter.

These are the statements under examination. They share a single, defining analytical characteristic: they treat the current 650 vehicles per day as the permanent, immutable demand ceiling for any future crossing. Not one of the documents above makes any reference to induced demand, suppressed demand, or the established transport economics of ferry-to-fixed-link transitions.

2. The Analytical Flaw: Treating Constrained Supply as Evidence of Demand

The McPeak 356-year payback calculation is arithmetically simple. It takes 650 vehicles per day, multiplies by the ferry fare of £7.70, reaches £5,000 per day, and divides that into £650 million. It reaches a headline figure designed to close down discussion.

The flaw is fundamental and it has two dimensions.

The first is the demand assumption. The calculation treats 650 vehicles per day as though it represents the demand that a permanent crossing would serve. It does not. It represents the demand that a constrained, unreliable, limited-hours, weather-dependent, 34-per-cent-capacity ferry service is currently attracting. The distinction between observed constrained demand and potential unconstrained demand is not a matter of opinion. It is the foundational question in any transport appraisal.

DfI’s own traffic count data, from count points CP 444 (A20 Kircubbin), CP 512 (A22 Comber-Killyleagh), and CP 513 (A7 Downpatrick at Quoile), records approximately 29,050 vehicles per day on the roads feeding the Narrows crossing (Northern Ireland Traffic Count Data, 2018 to 2023). These vehicles are already travelling. Many have origins and destinations on opposite sides of the Lough. The McPeak calculation contains no acknowledgement of this figure, no consideration of what proportion of those journeys represent suppressed crossing demand, and no reference to any origin-and-destination survey that might have established the relationship between road flow and crossing potential.

The second dimension is the tolling assumption. The calculation uses the current ferry fare of £7.70 as the revenue figure for a permanent crossing. This conflates a subsidised public ferry fare with the revenue model of a permanent crossing infrastructure asset. A bridge crossing at Strangford would not necessarily be priced at the ferry fare. It could be free to cross, subsidised, or tolled at a rate reflective of the journey time saving it delivers. The McPeak calculation does not model any of these alternatives. It uses a single input — the existing ferry fare — and applies it to a demand figure that is itself a product of the ferry’s operational constraints. The circularity is complete.

3. The Induced Demand Omission: A Critical Professional Failure

Standard transport appraisal methodology, as set out in the Department for Infrastructure’s own adopted framework — Transport Appraisal Guidance (TAG), referenced in the DfI publication “Incorporating Environmental and Climate Considerations into Business Cases” (Department of Finance, September 2025) — requires that demand modelling for a new or replacement infrastructure asset accounts for three distinct demand categories: existing demand diverted from alternative routes; suppressed demand released by improved accessibility; and induced or generated demand created by the economic activity that improved connectivity stimulates.

The McPeak calculation addresses none of these three categories. It takes observed ferry usage and treats it as the totality of what a permanent crossing would serve. No professional transport appraisal methodology would regard this as adequate, and the DfI “Raising a Concern” investigation’s own finding that the advice was given as a “guesstimate” and a “very rough cost estimate” implicitly acknowledges its limitations.

The consequence is that the 356-year figure — which has been communicated to Ministers, to elected representatives, and into the public domain as a meaningful indicator of the crossing’s economic case — is calculated entirely without the demand uplift that every comparable fixed-link study in these islands has recorded.

4. What Comparable Evidence Shows About Demand After Fixed Links Open

The HITRANS Corran Narrows Fixed Link Feasibility Study (Stantec UK/COWI, 2020) — the most directly comparable professional study available to this campaign — documents eleven Scottish fixed-link case studies. Traffic generation factors recorded include 5.7 times the pre-existing ferry AADT at the Berneray Causeway after seven years, and 22.4 times at the Eriskay Causeway after five to six years. The study notes explicitly that the primary driver of uplift magnitude is the quality of the predecessor ferry service: the poorer the service, the larger the induced demand effect.

The Strangford Ferry operates with weather cancellations, mechanical interruptions, a 22:45 operating ceiling, and at approximately 34 per cent of its theoretical vehicle capacity (Freedom of Information disclosure, DFI-2024-0366). By the HITRANS study’s own analytical framework, it falls squarely within the category of predecessor services most likely to generate the largest demand uplifts following replacement.

The Cleddau Bridge in Pembrokeshire, which replaced a ferry crossing in 1975 — and from which the MV Portaferry vessel was directly sourced — recorded 885,900 crossings in its first year and approximately 4,745,000 annual crossings by 2024, a twenty-fold increase over 49 years (SLC Comparative Analysis, campaign project file: SLC — Cleddau Bridge v Ferry Traffic). The Strangford Ferry, over the same 49-year period, has recorded zero net growth.

Applying even the most conservative Cleddau analogue — 15 per cent of Cleddau’s traffic growth trajectory — produces approximately 1,283,000 annual crossings by Year 30, equivalent to approximately 3,515 crossings per day. That is more than five times current ferry volumes, achieved on the most conservative scenario. Applying a 30 per cent Cleddau trajectory produces approximately 2,119,000 annual crossings by Year 30, approximately 5,805 crossings per day — nine times current ferry volumes.

None of these projections are unreasonable. All are derived from documented empirical precedent. None of them appear anywhere in the DfI official advice base.

5. The “False Hope” Statement: An Institutional Position Without Evidential Support

The McPeak memorandum of 22 August 2024 (FOI DFI-2024-0412) contains a further statement that requires direct examination. It reads: “Taking forward a feasibility study is not recommended as it would require public funding and divert resources away from other priority work. If taken forward only to discount the possible options, it would likely give false hope to elected representatives and the public of the possibility of a permanent crossing.”

This statement is remarkable in its implications. It asserts, in advance of any feasibility study, that the outcome of such a study would be to discount the crossing. It then uses that asserted negative outcome as the reason not to conduct the study. This is not a professional assessment. It is a predetermined conclusion used to prevent the instrument that would test it.

A TAG-compliant feasibility study exists precisely to produce objective findings, positive or negative. If DfI’s assumptions are correct and the crossing does not represent value for money, a properly conducted study will find that. If DfI’s assumptions are wrong — as the weight of comparative evidence suggests they may be — the study will find that too. The purpose of the study is to answer the question. The McPeak memorandum effectively argues that the answer is already known and that finding it out would be harmful. This is not consistent with any established framework of public sector appraisal and is directly contrary to the principles set out in the DoF Better Business Cases NI guidance (Department of Finance, September 2025 version).

6. The Net Position

The DfI official position, as disclosed through FOI and formal correspondence, rests on a static demand assumption — that 650 vehicles per day represents the demand a permanent crossing would serve — that has no methodological basis in standard transport appraisal and is contradicted by every comparable empirical study available.

The McPeak 356-year payback figure, which has been the effective anchor of DfI’s refusal, was calculated without induced demand, without suppressed demand release, without origin-and-destination analysis, without tolling scenario modelling, and without reference to any of the comparable fixed-link studies that are standard inputs to the type of appraisal DfI conducts for every other transport proposal it evaluates.

The appropriate professional response to that position is not to accept it. It is to require that DfI apply to this proposal the same TAG-compliant standard it applies to every other transport investment decision: independent, structured, evidence-based appraisal. That is what a feasibility study delivers. That is precisely what DfI has declined to commission.

Primary sources: DfI internal memorandum COR-1578-2024 (Mark McPeak, DRM Southern Division, 22 August 2024; David Porter, Head of Division, 30 August 2024), disclosed under FOI DFI-2024-0412; TOF-0467-2025 (Ian McClung, DfI Head of Consultancy Services, 24 October 2025); Sian Kerr, Director, Transport Planning and Policy Directorate, “Raising a Concern” outcome letter and Annex A (19 January 2026); HITRANS Corran Narrows Fixed Link Feasibility Study (Stantec UK/COWI, 2020); SLC Comparative Analysis: Cleddau Bridge v Ferry Traffic (campaign project file); FOI DFI-2024-0366; Northern Ireland Traffic Count Data, CP 444, CP 512, CP 513, 2018 to 2023; DoF Better Business Cases NI (Department of Finance, September 2025); DfI “Incorporating Environmental and Climate Considerations into Business Cases” (Department of Finance, September 2025).

A NOTE TO THE READER


You have just spent approximately eight to ten minutes reading this analysis. During that time, Northern Ireland’s confirmed infrastructure cost overrun — the gap between what was announced to the public and what projects now cost — increased by somewhere between £4,800 and £6,000.


That figure accumulates at approximately £10 every second, every hour, every day, on projects already announced, already committed, already in the system.


The Department for Infrastructure tells us that a feasibility study into the Strangford Lough Crossing would not be a good use of public funding. Indeed !


The cost of a TAG-compliant feasibility study for a crossing of this nature would be in the region of £250,000 to £500,000 — a sum consumed entirely within the confirmed overrun accrual of seven to fourteen hours.
Not days. Not weeks. Hours.


We are not asking for the crossing to be built on faith. We are asking for the question to be answered properly, using the same professional methodology DfI applies to every other transport investment it evaluates.
The cost of not asking that question is already being counted — second by second.


Track the NI infrastructure cost overrun in real time at https://ktbcpdni.netlify.app/