Triangular distributions

I am doing some modelling work which revolves around passengers
arriving at an airport to depart on an aircraft. In order to simulate
passenger arrivals times prior to the aircrafts departure I am
generating a random arrival time with a range of 2 hours to 30 minutes
before departure. This is probably OK however statistically
passengers would not arrive randomly, but a distribution curve would
be a more accurate representation of how passengers arrive.

My question therefore is, has any-one had any experience creating
triangular distributions in Access and if so could they point me in
the right direction.

Any help would be greatly appreciated.

Regards
Trevor