The number of traffic-related fatalities in Denmark is around 200 per year, see e.g. [1]. Blood clots appear in 4 per 1M people (UK numbers, [3]) or 10 per 1M (Denmark numbers, [2]). That would mean about 24 to 58 Danish people would get blood clots from their first shot. Denmark had 2447 covid deaths, [4]. If you zoom in on certain age-groups, then perhaps Denmark's decision could still make sense, though.
[1] https://www.statista.com/statistics/573861/number-of-traffic...
[2] https://www.thelocal.com/20210318/ten-blood-clot-cases-found...
[3] https://cosmosmagazine.com/health/medicine/covid-19-vaccinat...