President Trump has announced the outlines of an ambitious $1 trillion agenda to rebuild America’s crumbling roads and bridges, outdated water systems and dilapidated public buildings. While the general goal of investing in infrastructure has broad bipartisan support, Mr. Trump’s call for relying heavily on private financing has come under fierce criticism. As consultants and advocates for such public-private partnerships, we believe those attacks are wrongheaded.

Critics assert that public-private partnerships enrich investors at taxpayers’ expense, are more expensive and less accountable, lead to public bailouts and do little to help rural areas. But this ignores strong evidence to the contrary in states like Pennsylvania, New York, Florida, Colorado, North Dakota and California.

The private sector is already involved in building our infrastructure, but usually with public funds. President Trump would allow private investment in those projects for a good reason: private funds increase accountability. As a partner in a public project, the private sector is on the hook for cost overruns and delays and may be contractually obligated to pay hefty fines or other penalties when the results are lackluster.

If a project is behind schedule or over budget, private companies pay a hefty fee and make up the difference, since they financed that project. If a project isn’t maintained and operated according to strict standards throughout the contract, the private sector could pay substantial fines. The same is often not true of purely publicly financed projects.