"activities-portland-1-v1.dat" contains the activities performed by each
protoentity in the Portland data set.  The time between activities is
used to travel from activity to activity.
Each line has the following fields:

Household Id - Household containing the person
Person Id - Id of the person.
Activity Id - Id of the activity, numbered sequentially for each household
Purpose - The purpose of the activity 
        0 - Home
        1 - Work
        2 - Shop
        3 - Visit
        4 - Social/Recreation
        5 - Other
        6 - Pick up or drop off a passenger
        7 - School
        8 - College
Start Time - Time the activity starts, in seconds past midnight
Duration  - Duration of the activity, in seconds
Location - Id of the location at which the activity takes place