Motorists are being urged to be wary of several "hot spots" at interchanges and exit and entry ramps when the first major stage of the WestConnex opens to traffic next month.

While a final opening date is yet to be revealed for the toll road, transport officials confirmed the ribbon would be cut on the M4 East between Homebush and Haberfield in July. The project is in the final stage of commissioning, and still requires sign-off from state regulators.

The M4 East will open to motorists next month. Credit:AAP

"It will be July," M4 East project director Terry Chapman said on Friday of the opening.

"We are in the final commissioning phase at the moment and we're not going to open until we get all those systems finally signed off. It is in the coming weeks."