Table B-1c. Estimated Standard Errors of Percentage for Hazardous Material Shipment Characteristics by Mode of Transportation: Percent of Total for 2002 and 1997
Table B-1c. Estimated Standard Errors of Percentage for Hazardous Material Shipment Characteristics by Mode of Transportation: Percent of Total for 2002 and 1997
[Estimates are shown as percents and are based on data from the 2002 and 1997 Commodity Flow Surveys]
Mode of transportation | Value | Tons | Ton-miles | |||
---|---|---|---|---|---|---|
2002 | 1997 | 2002 | 1997 | 2002 | 1997 | |
All modes | – | – | – | – | – | – |
Single modes | 0.2 | 0.2 | 0.2 | 0.2 | 0.9 | 3.1 |
Truck | 1.4 | 1.6 | 1.3 | 1.9 | 2 | 2.6 |
For-hire truck | 1.2 | 1.1 | 0.8 | 1.2 | 1.8 | 2 |
Private truck | 1.3 | 1.2 | 1.3 | 1.1 | 1.1 | 1.2 |
Rail | 0.4 | 0.7 | 0.3 | 0.5 | 1.6 | 2.9 |
Water | 0.8 | 0.8 | 1.3 | 1.2 | 2.2 | 2.8 |
Air (includes truck and air) | – | 0.6 | – | – | – | – |
Pipeline | 1.2 | 1 | 1.4 | 1.6 | S | S |
Multiple modes | 0.2 | 0.2 | 0.2 | 0.2 | 0.9 | S |
Parcel, U.S.P.S. or courier | 0.1 | – | – | – | – | – |
Other multiple modes | 0.2 | 0.1 | 0.2 | 0.2 | 0.9 | S |
Other and unknown modes | 0.2 | 0.2 | 0.1 | - | 0.4 | 0.1 |
KEY:
– Represents and estimate equal to zero or less than
1 unit of measure.
S Estimate does not meet publication standards because of highly sampling
variability or poor response quality.
NOTE: The Introduction and appendixes give information on confidentiality protection, sampling error, nonsampling error, sample design, and definitions. Links to this information on the Internet may be found at www.census.gov/cfs.
SOURCE: Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, Hazmat Data, December 2004.