BTS | Table 1. Structure of 2001 NHTS Pre-9/11 and Post-9/11 Data Files

Table 1. Structure of 2001 NHTS Pre-9/11 and Post-9/11 Data Files

Data Files	Information Included	Record Level	ID Variables	Weight	Replicates
Pre-9/11 Person	These files include education level, worker status, occupation and employer information, driver status, annual miles driven, country of birth, income, and other characteristics of the person.	One record per person (person whose assigned travel date is before or on 9/25/2001)	HOUSEID and PERSONID	WTPRPRE	PERPRE1-PERPRE99
Post-9/11 Person	These files include education level, worker status, occupation and employer information, driver status, annual miles driven, country of birth, income, and other characteristics of the person.	One record per person (person whose assigned travel date is after 9/25/2001)	HOUSEID and PERSONID	WTPRPST	PERPST1-PERPST99
Pre-9/11 Long-Distance Trip	Information on these files includes trip purpose, trip distance, and mode of transportation used to and from destination. Household and person characteristics are included with long-distance trip characteristics.	One record per long-distance trip (trip taken by person who is in the pre-9/11 Person-level data file)	HOUSEID and PERSONID	WTLDPRE	LDPRE1-LDPRE99
Post-9/11 Long-Distance Trip	Information on these files includes trip purpose, trip distance, and mode of transportation used to and from destination. Household and person characteristics are included with long-distance trip characteristics.	One record per long-distance trip (trip taken by person who is in the post-9/11 person-level data file)	HOUSEID and PERSONID	WTLDPST	LDPST1-LDPST99