In the incident, a woman punched the female victim in her car at the intersection of Great Northern Highway and Reid Highway.
Police said the attacker got out of her car, approached the victim�s car, punched her in the face several times, then removed and threw away the victim�s car keys.
Midland officer-in-charge Craig Davis said while it was unusual for road rage to get to the point of assault, it was important for motorists to settle down while driving.
�We all make mistakes behind the wheel; no one�s a perfect driver and there�ll always be a time when someone might not indicate enough or someone might make a minor mistake,� he said. �We just need to sit back, take a deep breath and just get on with it.
�Unfortunately it�s something that still happens every now and then and we just need to deal with it as quick as we can.�
Associate professor at University of WA�s Crime Research Centre, David Indermaur, said road rage was a reflection of a culture of accepting aggression.
�The cause of it, if anything, is cultural; to give one�s self permission to lose one�s temper and act aggressively on the road,� he said.
�Really what�s required to prevent it is a cultural shift.
�You can see road rage as an extension of aggressive driving so cases of aggressive driving should really be policed and prosecuted more.�
�The way we talk about aggressive behaviour very much becomes part of our cultural understanding; for example, when a footballer player assaults another football player on the field, we call it striking and that kind of diminishes it a bit.�
Dr Indermaur said the cause of road rage was in individuals and he had some advice for irate drivers.
�If you find yourself getting agitated behind the wheel, you need to look at what�s going on inside your mind and work towards constructing a peaceful place inside your mind,� he said.
�Whether it�s putting on music or just accepting the drive home from work, or wherever you�re driving, can be an occasion for relaxation rather than agitation.�
Midland Police are continuing investigations into the assault, which occurred on April 30 about 11.30am.
They are looking for a solidly built female with straight long black hair and tattoos, dark-skinned, about 30 years old and driving a burgundy four-wheel drive.
A man remained seated in the vehicle during the assault and is described as dark skinned, around 30 years old, with a slim build and beard.
Anyone with any information can call Crime Stoppers on 1800 333 000.