Incompatibility between the small car and certain aspects of highway design is a factor in the toll of highway deaths and injuries. Tort liability implications are significant because potential liability is a factor in inducing greater compliance with safety standards, and, thus, in reducing highway deaths and injuries. The major defense to governmental tort liability is based on exemption from liability for discretionary activities. As a general rule, for several years, approval of design of the highway was considered discretionary and not subject to "second guessing" by courts. The trend in recent cases has been to find exceptions to the design immunity rule in light of changed conditions or based on evidence that the design was approved without adequate prior study or lacked a reasonable basis. Manufacturers are held to a standard of reasonable care in design to provide a reasonably safe vehicle, taking into consideration the environment in which it is used.