A micromort (from micro- and mortality) is a unit of risk defined as a one-in-a-million chance of death.
The micromort concept was introduced by Ronald A. Howard who pioneered the modern practice of decision analysis.
[3] Micromorts for future activities can only be rough assessments, as specific circumstances will always have an impact.
However, when looking at their day-to-day actions (e.g., how much they are willing to pay for safety features on cars), a typical value for a micromort is around $50 (in 2009).
[35] Since road improvements have the effect of lowering the risk of large numbers of people by a small amount, the UK Department for Transport essentially prices a reduction of 1 micromort at £1.60.