One of the arguments put forward in favour of PPPs is that they are more likely to be on time and on budget. The evaluation therefore sought to test whether this was true and, if not, were delays due to the Promoter, the Provider, or outside factors? On the transport project referred to above, there were long delays in agreeing detailed project specifications with the Promoter, which delayed completion and increased costs. Similarly, there were delays and cost overruns on a road infrastructure project, due to a combination of geological problems and slower than expected civil works. There were cost overruns, but no delays, on three projects: an urban motorway (mainly on the public sector element of the project), an inter-city motorway (the Provider decided to build an extra lane on the motorway), and a second road infrastructure project (due to a combination of restrictions on the civil works, and the need to carry out additional work for safety reasons). The extra costs on both road infrastructure projects were carried by the Promoter.
There are also potential issues where the Provider is controlled by construction companies which may look for short-term benefits at the expense of long-term costs. On a motorway and a road infrastructure project, the Providers are led by contractors and the scope of the construction work may have been expanded prematurely. On the motorway, this was carried out during construction and without prior lender consent. In the case of the road infrastructure project, additional works were correctly included as part of the bid. These additional works benefited from economies in construction, but the Providers now have to carry a greater debt burden, without sufficient revenues to fully support them at this stage.