Table 3.

Conceptual Haddon matrix of factors in road traffic fatalities in the setting of adverse weather and road conditions

Phase	Host	Agent	Social environment	Physical environment
Pre-Event	Severe weather driving experience and training	Specific adverse weather equipment affecting performance and thus energy transfer (e.g., tire chains)	Transportation infrastructure (e.g., road network) preparedness for adverse weather. Adverse-weather speed limits	Weather-resilient signage. Road surface preparation (e.g., salt). Road and bridge design (e.g., drainage capacity)
Event	Ability to perform emergency and evasive maneuvers	Stopping distance. Anti-lock brakes. Vehicle performance characteristics. Safe airbag deployment		Collision barriers
Post-Event	Capacity to withstand adverse environmental and injury exposures	Vehicle crash notification system	Transportation planning and traffic flow management to facilitate emergency medical and safety response	Emergency medical service arrival and transport time. Feasibility of air transport

Some possible phase-specific factors affected by adverse weather and road conditions. Factors wherein adverse weather conditions are not considered a significant part of the causal pathway, e.g., use of active and passive restraints, are not listed