There is no simple answer to comparative safety of gliding and driving,
and few statistics that I am aware of to make a numerical comparison.
Among the bases of comparison one might try are fatalities per event
(launch vs car journey), per unit of time spent doing it, and/or per
person doing it, but data for any two equivalents are hard to come by.

One very crude measure is say 24 million drivers ( a guess - use your
own figure if you think that's wrong) in the UK kill about 4000 people a
year (which includes passengers and other road users) - say 1 per 6,000
drivers.

Gliding has less than 10,000 pilots (an overstatement because not all
are P1 each year) and we have about 5 fatalities (nearly all being
participants) each year - say 1 per 2,000. So this method of counting
gets at least 3 times the risk. Increasing driver/passenger numbers and
reducing the number of active pilots would worsen the ratio.

On the other hand, people exposed to gliding risk each year could
include all 30,000 temporary members (most having one or two air
experience trial lessons), just as car fatalities include passengers.
Redo the sums accordingly if that helps.

People at risk from gliding include those on the ground. Although such
fatalities are very rare, they are not unknown - I knew one person who
was killed by a cable snapping back when released from a tow truck, and
I know of one woman killed on a public footpath by a glider landing next
to it. One could add in the friends, families and hangers on at gliding
sites to increase the base and so reduce the incidence rate.

These latter refinements bring in more people "at risk" but at a much
lower real level of risk than somebody who is in the cockpit many times
in a year. But then, the car fatalities include people who are drivers,
and also those who are front seat passengers and rear seat passengers -
the latter generally being at much lower risk if they are strapped in.
Once you start trying to refine the risk levels, there is no end -
competition and aerobatic pilots are probably generally more at risk
than careful local-only pilots, but stupid local-only pilots who
mishandle cable breaks are very much at risk.

The two risks I know of where you cannot personally reduce the level to
zero by your own efforts - airframe integrity, and collision from the
blind spots - are among the lowest of all incident levels. So we are
left with most of the risk being in our own hands - the nut behind the
stick is the biggest risk factor.

Chris N.