It provides only 489 car spaces, including 15 spaces for the disabled, eight motorcycle spaces and 40 dedicated spots for securing bicycles.

Work on the project, which includes road works, started in April 2010 and final works including landscaping, painting and electrical works are now being completed.

A Transport Construction Authority (TCA) spokeswoman said there would be about 1000 parking spaces in the Blacktown CBD after its completion.

A Blacktown Transport Coalition group spokesman said this number could not solve the acute shortage of commuter parking in the area.

He said commuters would need at least 5000 parking spots to encourage more people use public transport.

The TCA spokeswoman said its other works included the construction of a pedestrian link from First Avenue to Humphries Lane and a forecourt area on Humphries Lane.

She said the final stage involving roadworks on Third Avenue eastbound to provide a new right-turn lane into Prince Street would start in August and be completed in December.

"The new right-hand-turn lane would facilitate the flow of traffic to the car park," she said.

"To widen the roadway for this, existing services including gas, water, electrical and communications will be moved north of their existing locations on the northern side of Third Avenue."

Works will also cause the loss of up to 10 timed parking places on Prince Street south of its intersection, and parking on Third Avenue will be temporarily unavailable until August.

See story on page 3 on rail transport as Blacktown's population is due to explode over the next two decades.