Step 1 — Relevant industry

Ferrovial S.A. is primarily an infrastructure operator/developer with major toll road, airport, and other infrastructure project interests. Among the supplied methodologies, the closest fit is Transportation Infrastructure. Under that methodology, the core financial ratio is FFO to debt, which matches the requested metric.

Step 2 — Estimate Adjusted EBITDA

Reconstruct EBITDA from operating profit before D&A:

- Profit from operating activities, 2022: EUR 423m
- Amortisation expense, 2022: EUR 299m

Reported/reconstructed EBITDA:

\[
EBITDA = 423 + 299 = 722 \text{ m}
\]

S&P adjustments/normalization:
- Operating fair value adjustment was small: +EUR 1m embedded in operating profit. To estimate underlying EBITDA, remove this gain:
\[
722 - 1 = 721 \text{ m}
\]
- No sufficient data for proportional JV EBITDA, pension adjustments, guarantees, or other normalizations.
- Lease adjustment: under S&P, lease liabilities are added to debt and lease-related expense is generally reflected in EBITDA. Given limited P&L lease expense data, no additional EBITDA lease adjustment is made beyond using reported EBITDA.

Estimated Adjusted EBITDA:

\[
Adjusted\ EBITDA \approx 721 \text{ m}
\]

Step 3 — Estimate FFO

Baseline:

\[
FFO = Adjusted\ EBITDA - cash\ interest - cash\ taxes
\]

Use cash-flow statement items:

- Interest paid classified as financing activities, 2022: EUR 329m
- Income taxes paid/refund classified as operating activities, 2022: EUR 82m

\[
FFO = 721 - 329 - 82 = 310 \text{ m}
\]

Estimated FFO:

\[
FFO \approx 310 \text{ m}
\]

Step 4 — Estimate Adjusted Debt

Reported debt at 2022 year-end / 2023-01-01:

Infrastructure project debt:
- Noncurrent debt securities and bank borrowings of infrastructure projects: EUR 7,893m
- Current debt securities and bank borrowings of infrastructure projects: EUR 74m

Excluding infrastructure project debt:
- Noncurrent debt securities and bank borrowings excluding infrastructure projects: EUR 2,883m
- Current debt securities and bank borrowings excluding infrastructure projects: EUR 803m

Reported borrowings:

\[
7,893 + 74 + 2,883 + 803 = 11,653 \text{ m}
\]

Lease liabilities:
- Noncurrent lease liabilities: EUR 120m
- Current lease liabilities: EUR 64m

\[
Leases = 120 + 64 = 184 \text{ m}
\]

Gross debt including leases:

\[
11,653 + 184 = 11,837 \text{ m}
\]

Eligible cash:
- Cash and cash equivalents: EUR 5,130m

S&P typically does not necessarily net all cash, but with the data provided and no haircut/cash-trapping detail, use reported cash as eligible cash. Therefore:

\[
Adjusted\ Debt = 11,837 - 5,130 = 6,707 \text{ m}
\]

Estimated Adjusted Debt:

\[
Adjusted\ Debt \approx 6,707 \text{ m}
\]

Step 5 — FFO / Adjusted Debt

\[
FFO / Adjusted\ Debt = 310 / 6,707 = 0.0462204
\]

Rounded to four decimals:

<answer>0.0462</answer>