This may have been a traffic survey which is done in the planning stages of a town bypass / ring road or similar. I participated in one of these about 7 years ago in Mullingar, which now has its bypass in place I believe.
Purpose of such a survey is to find out where you are coming from and going to, to understand the pattern of traffic within a town, and to figure out whether this traffic will end up on the bypass or not, where junctions with the bypass are needed etc.
In the course of a day, we had one or two individuals who were suspicious of our motives and didn't want to answer the questions. We let them continue on their paranoid little way....