The landslide took place near the Adoshi Tunnel which is close to Lonavala.
The Pune-Mumbai expressway was kept out of bounds till late on Sunday night after a landslide killed three persons in the afternoon.
One of the passing cars had been completely smashed after tons of earth and rocks landed on the highway near the Adoshi tunnel, close to Lonavala, blocking a portion of the road. (See Pictures)
Both lanes of the busy expressway had been closed immediately for traffic. Later in the evening, one lane -- for traffic towards Pune -- was cleared.
But traffic towards Mumbai could not be restarted as continuous rains had loosened the soil and increased the possibility of more landslides, officials said.
Sources say the iron holding on the side of the expressway has become old and so the area has become landslide prone, especially during monsoons.
The highway police have appealed to motorists to use the old Mumbai-Pune road. The railways ran two special trains between the two cities to take the pressure off the road.
The operation to clear the debris from the roads is on, the Highway Police said.
The Mumbai-Pune expressway, a nearly 100-km-long, six-lane road, was built in 2002. It usually sees high traffic over the weekend, with people travelling from Mumbai to Pune and vice-versa.
The traffic on the expressway was hit last month too, after a landslide near the Khandala tunnel. No casualties were reported.