Train crowds will slow down Sydney network

More people are cramming onto Sydney trains than expected, and unless new plans are made soon, the network will struggle to cope within two years.

The NSW Auditor General says current plans will not be sufficient to keep trains running on time if a recent spike in commuter numbers continues.

Even if passenger numbers fall to predicted levels, an upgrade will be needed after 2019, a report released on Tuesday says.

Overall the Auditor General found trains were exceeding punctuality targets, but certain services, including the North Shore line and East Hills express, were often late in afternoons while intercity trains lagged behind their more punctual suburban cousins.