Large businesses in Sydney's north are increasingly concerned about how the state government plans to transport thousands of commuters each day while the Epping to Chatswood rail line is shut for seven months.

Ryde Council and Australia's second-largest telco, Optus, have sought a meeting with Transport Minister Andrew Constance to get "some clear and certain undertakings" about plans to upgrade transport infrastructure at Macquarie Park to cope with the temporary closure of the line between Epping and Chatswood in late 2018.

The closure of the heavy rail line presents a major logistical challenge for those at Macquarie Park – the second largest business precinct in Sydney after the CBD – because it is crucial to helping transport about 40,000 people to and from the area each weekday.

Ryde mayor Bill Pickering said the council and businesses were concerned about the "lack of information and certainty" on when the shutdown of the line would occur.