The DoP was initially critical of the Harbour Street exit and its potential to increase congestion in the CBD. The concern was that this exit would relocate a significant amount of traffic to other parts of the City rather than remove the traffic entirely from the City. The DoP said the Harbour Street exit could erode the benefits of the CCT in the long term.
Despite these concerns, the project proceeded with the Harbour Street exit because the RTA argued that removing this exit would reduce the project's financial attractiveness. Removing the exit would reduce traffic by 23 per cent, hence significantly reduce toll revenues. However, to offset this impact a congestion toll on the exit is foreshadowed in the Condition of Approval as an option if infiltration of traffic into the City becomes a critical issue.
The DoP said in the Director-General's Report:
The Department concludes that the strategic outcome of the Harbour Street exit has the potential to conflict with the benefits of a 'Cross-City' Tunnel. At best, the Harbour Street exit would relocate traffic to a different part of the CBD, but at worst, could lead to significant infiltration of traffic back into the CBD as well as potential pressure for more parking in the CBD. However, as indicated above, the RTA has expressed concerns that its removal would have serious implications for the financial viability of the project given its significant use, particularly if the principle of 'no cost to government' is to be preserved ... Should infiltration become a critical issue, it is recommended that further traffic management measures be imposed including the option of a congestion toll on the exit.
Source: Director-General's Report, Environmental Impact Assessment, Proposed Cross City Tunnel, Kings Cross to Darling Harbour Volume 1. Department of Urban Affairs and Planning, September 2001, page 22.
The viability of the tunnel was also a significant factor in the negotiated outcome and final configuration of the road change relating to access to the Cahill Expressway. See Exhibit 4.6.