This report is intended as a follow-up to the April 1998, February 1999 and January 2000 NYPIRG Straphangers Campaign surveys, Subway Shmutz: Cleanliness in New York City Subway Cars. The methodology followed in this survey is largely identical to that used in our last report. One adjustment to the methodology of the 1998 and 1999 surveys is noted below.

In July 1997 and again in August 1999, our project directors accompanied members of MTA New York City Transit Passenger Environment Survey (PES) staff on an in-field mock rating of some 20 cars on two subway lines. The session included clarification of New York City Transit’s own rating system (see below). We also received the survey form used by PES staff. The PES looks at several measurements of the subway car environment, including car and seat cleanliness. Our survey is an in-depth measurement of car floor and seat cleanliness only.

Rating System

PES surveyors evaluate the cleanliness of subway car floors and seats with a four-level rating system in which a score of 1 represents the highest cleanliness rating and a score of 4 represents the lowest. The following definitions are from the New York City Transit’s Passenger Environment Survey, 1st Quarter 1997 and are still in use:

Score PES terminology PES definition

1 Basically dirt free.

2 Occasional "ground-in" spots but generally clean.

3 Dingy floor, one or two sticky dry spots.

4 Heavy dirt; any opened or spilled food, hazardous (e.g. rolling bottles) or malodorous conditions, sticky wet spots, any seats unusable due to unclean conditions.

The PES notes that "the nature of the dirt (e.g. spilled food, malodorous floor/seat condition, etc.) is also considered in addition to just the volume."*

In our study, we used a numbered system identical to the one listed above. However, we modified the terms to describe each rating. We believe our definitions more accurately reflect the meaning behind each score:

1 None Extraordinarily Clean

2 Light Clean

3 Moderate Dirty

4 Heavy Heavily Dirty

Page Two–Methodology/Subway Car Cleanliness

Our project directors trained nine additional surveyors. During the period October 2, 2000 to January 4, 2001, this team rated exactly 100 subway cars on each of 20 lines^*. This is similar to the size of PES samples. We dropped from consideration three lines operated by New York City Transit–the Grand Central-Times Square, Rockaway and Franklin Avenue Shuttles–because they are not rated in the PES survey. The measurements were taken both on weekdays and weekends, during rush hours, and during evening and overnight hours.

All survey data submitted was visually inspected for error and then coded for entry into a Microsoft Excel 8.0 spreadsheet format. After entering the data, we calculated both by-line and systemwide totals. The percentage of cars rated "dirty" and "heavily dirty" were combined to offer a measurement of the proportion of cars with an unacceptable level of interior dirt. Similarly, "extraordinarily clean" and "clean" rating totals were combined to reflect the proportion of subway cars with an acceptable level of dirt. Systemwide car cleanliness proportion is significant at the .05% confidence level within plus or minus 3%. By-line cleanliness levels are significant at the .05 confidence level within plus or minus 8-10%:

Table one notes that in the period between the 1999-2000 and 2000-2001 surveys, car conditions improved significantly systemwide. By-line car conditions improved on ten lines and deteriorated on one line. Significance of these results was established with a one-tailed Z-test at the .05 level.

The 2000-2001 survey’s finding of improvement mirror the trend in MTA New York City Transit own Passenger Environment Surveys. The transit agency’s ratings for the third quarter of 2000 have not been released, so no direct comparison to the Straphangers Campaign survey is possible. In past surveys, New York City Transit has rated subway cars as considerably more clean than has the campaign’s surveys.