Last-minute toll concessions are being negotiated for Route Three amid fears cash-strapped motorists may avoid the new $7.25 billion expressway.
The 10-km country park section of the route, which includes the 3.8-km Tai Lam Tunnel, is expected to slash peak hour trips between Yuen Long and Central by two-thirds when it opens on Monday.
Transport officials and Route Three management hope to stop a repeat of problems facing the under-used Western Harbour Crossing, which costs $30. They plan a publicity blitz, a freeze on the $15 toll and discounts.
But Transport Department officials admitted traffic flow might not meet the 130,000-vehicle daily projection made before the economic downturn.
Chief Engineer (New Territories west) Lee Yan-ming said the department had installed more than 120 signboards directing motorists to the route, and it was discussing further promotion measures with the management company.
'The two-way flow of about 65,000 vehicles per day of course depends on economic and other factors,' Mr Lee said.
Hong Kong Automobile Association spokesman Jackson Ho Yee-tak said it was financially one of the worst times for motorists, who he warned would avoid the route for a cheaper option.