Network analyst: Mean travel time for first 80% to reach a destination

Discussion created by toreb-geodata-no-esridist on Jun 22, 2010
Hi. I need to do the following, but I can't seem to find the tool for it.

I have a distribution of 15 facilities.

Given unlimited time, I must find out the mean travelling distance for the first 80% of the population that reach a facility.
(incidents/demand points are point data of population, the population number varies amongst the points)

I've tried closest facility tool, but I can't seem to weight the incidents (I need to since each incident points equals a given population number, the "true" population which I shall do analysis for).

I tried location-allocation tool. I set travel time to unrealistic high, and 80% target market share. But It returns more than 80% of the demand points.

I hope someone has any ideas...

running arcinfo 10