We examined the robustness and reasonableness of the RTA's decisions to change surface road conditions related to the CCT. A widely held view is that the road closures and changes are not necessary, but have been introduced to force motorists into the tunnel to profit the operator. In our view this was not the case.

We found that the main objective of the road changes was to reduce through traffic in and around Central Sydney and to improve the public domain. However, the financial viability of the tunnel, and the RTA's understanding of 'no net cost to government', did influence some important planning decisions as the project progressed.

High patronage estimates also influenced the road changes, and to date have not been met. It was believed that the emptier roads would immediately attract other cars. So, roads were restricted causing considerable congestion and resentment.

Maintaining toll-free alternative routes was a key principle in the original design. But road restrictions added progressively meant that, in the end, there were no direct, convenient toll-free alternatives left.

There was extensive consultation with stakeholders about the road changes. But it did not capture the significant resentment among prospective toll payers. Loss of patronage from this resentment will hinder the achievement of the tunnel's main objective of reducing through traffic in the City.