The superior time performance of PPPs is often said to be due to financial incentives built into the PPP model. The service payment for service-payment PPPs does not commence until the facility is completed and services commence. Likewise, user charges can generally only be levied on a user-charge PPP once construction is completed.
Sometimes the SPV's revenue earning period will be structured so that early completion results in a longer revenue-earning period for the SPV, and late completion results in a shorter revenue-earning period. The SPV will often agree to share any revenue it earns during the 'additional' revenue-earning period with the D&C contractor. Most Australian toll road PPPs have included such a regime for the sharing with the D&C contractor of tolls collected by the SPV between the actual date of opening and the (later) contracted date for opening.
However, financial incentives for the timely completion of construction can also be built into traditional delivery models - for example, liquidated damages for late completion. Accordingly, the superior time performance of PPPs is more likely caused by the rigorous assessment by lenders and equity investors of risks that could delay construction, and the careful management of the D&C contract to ensure that the liquidated damages regime remains enforceable.