Waikato Police's Serious Crash Unit are investigating another death after a man was killed following a crash on State Highway 1B/Gordonton Rd on Tuesday night.

District Road Policing Manager Inspector Freda Grace says a woman was also left critically injured as a result of the fatal crash that occurred on the outskirts of Hamilton at about 5.20pm.

To enable a thorough examination the scene of the crash will be closed this morning to allow crash investigators to map the scene in daylight, from 10.30am to 11.30am. Traffic management staff will be on scene and diversions will be in place.

'The crash is still under investigation by the Waikato Serious Crash Unit so it's too early to confirm what has occurred,” says Freda.

'However, initial indications are that a northbound Nissan Bluebird car has crossed the centreline into the path of a southbound Mazda Tribute stationwagon.”

Freda adds that police are now awaiting the results of forensic examinations to complete the formal identification of the male driver of the Nissan who died in the crash.

The man was the sole occupant of Nissan, but there were two women travelling in the Mazda and both were taken to Waikato Hospital by ambulance.

One underwent surgery overnight and is described as being a critical but stable condition while the second woman is described as suffering minor to moderate injuries.

While the circumstances of the crash are under investigation, police are also working to determine what occurred in the moments leading up to the crash.

Freda says they have reports from witnesses of the Nissan possibly crossing the centreline in front of an oncoming truck shortly before the crash.

'We're continuing to piece together what may have occurred and what, if any, contributing factors there may have been,” she adds.

'This tragedy follows on from a very concerning weekend on Waikato roads that saw some very high speeds, 36 drivers processed for drink driving and two crashes in particular, where the intoxicated drivers were very fortunate to survive. Yesterday shows just how unforgiving our roads can be.”

Tuesday saw two fatal crashes on Waikato roads after a motorcyclist died following a collision with a car at an intersection in Tokoroa at about 3pm.