Three people were killed and 14 others injured after a van overturned on Route 443 near Shilat Junction on Thursday evening.
Ten Magen David Adom ambulances and six intensive care units evacuated the casualties to hospitals in Jerusalem and the Tel Hashomer Medical Center, three of them in severe condition, four in moderate condition and seven lightly injured.
Police traffic examiners said the van probably overturned after losing control, due to excessive speed.
The van was carrying Palestinians from the West Bank city Kalkilya, who apparently had been in Israel without appropriate permits.
Following the accident, Route 443 was shut to traffic travelling from Jerusalem to Tel Aviv. Although the reverse direction remained open, it has become heavily blocked.
The police are also checking whether the vehicle was stolen.
Shilat Junction, which is near the city Modi'in, has become known as an accident blackspot over the last few years after a series of fatal crashes.