Maintaining correct inflation pressure in tyres helps to keep vehicle handling and braking at its best, as well as improving fuel efficiency and tyre life. In addition it can prevent such events as tread separations and tyre blowouts which may cause loss of control of a vehicle and severe crashes such as rollovers. The Heads of Compulsory Third Party Insurance in Australia and New Zealand (HCTP) commissioned research to review and attempt to better quantify the role of under-inflated tyres in crash cause, injury cause and environmental costs. The main aim of the review was to locate all the relevant material and attempt to quantify the role of tyre factors in crashes and the possible safety and environmental benefits from improved conformance with recommended tyre inflation pressures.