An audit of planning documents for the Santo Domingo monorail has found that the project’s socioeconomic analysis was carried out only for the pre-selected technology, with no comparable economic evaluation of alternatives including the city’s existing metro system.
The findings were published by Carlos Bonnelly Ginebra, a transport economics consultant, as part of a series examining documents submitted to the General Directorate of Public Procurement (DGCP) by the Ministry of Finance and Economy. The documentation was released in response to demands filed by engineer Mariano German, who brought a formal challenge before the DGCP seeking to subject the public investment to standard planning and procurement rules.
Bonnelly Ginebra said the cost-benefit study contained in Annex 7 of the planning file showed a positive return for the monorail under its own assumptions. Because the study was provided only as a PDF, with no original electronic model or formulas, the audit reconstructed the economic flow in an Excel workbook. That reconstruction reproduced an economic internal rate of return of 10.55 percent, consistent with the published figure of 11 percent, and an approximate economic net present value of USD 268.4 million. He said those results confirmed the monorail would outperform a do-nothing scenario.
However, he said a positive net present value did not mean the monorail was the best available option. The situation, he wrote, resembled showing that one of four possible roads leads to a destination without establishing whether it is the shortest, safest, or cheapest route.
Metro ranked first in every robustness test
A separate analysis, Technical Note III, reconstructed a multicriteria comparison used in 2025 to rank the monorail, the metro, the tram-train, and the suburban train. Bonnelly Ginebra said a robustness test using 36 combinations of demand levels, monorail frequency, and capacity weighting placed the metro first in every case. The monorail did not rank first in any combination. He said those results did not constitute a new technology-selection study but demonstrated that the decision in favour of the monorail was not robust within the domain analysed.
After that selection, he said, Annex 7 calculated costs and benefits for the monorail alone, closing the process without the fundamental economic test. No comparable net present value exists for each technology, and no homogeneous evaluation covers investment, operations, maintenance, replacements, expansions, residual value, capacity, and service quality across options.
Legal framework and existing infrastructure
Bonnelly Ginebra said the missing comparison violated Dominican law and regulations. Law 498-06 requires economic and social evaluation in pre-investment studies and demands efficiency in resource allocation. Decree 493-07 requires analysis of multiple alternatives. Dominican technical guidelines, he said, align with international best practices in requiring options to be compared on common bases before selecting the one that makes best use of social resources.
He said the omission was especially significant given Santo Domingo’s existing metro infrastructure. The capital already operates two metro lines with a control centre, workshops, and depots. Expanding the metro could reinforce network effects and draw on assets already in place, he argued, while introducing the monorail would require a separate technological platform with its own systems, maintenance requirements, spare parts, and operational learning curve. The audit said those synergies and duplications were absent from the analysis.
Bonnelly Ginebra concluded that the socioeconomic study did not demonstrate the monorail would maximise net social benefit. The project file, he said, offered no serious comparison with the metro. Demonstrating that the monorail was viable was not sufficient; the requirement was to demonstrate it was the better choice for Santo Domingo.
