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Guidebook for Conducting Local Hazardous Materials Commodity Flow Studies (2011) / Chapter Skim
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Appendix E - HMCFS Sampling and Scheduling
Pages 118-121

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From page 118...
... recommend 24-, 48-, or even 72-hour samples. Neither of these are practical for most local HMCFS because • Traffic levels may not be known or highly variable by time of day, day of week, or season of year; • Long duration samples can be very difficult to achieve in practice when conducted manually, as is the case for HMCFS data collection of UN/NA placard IDs; or • A high level of sampling may not be required to develop a general characterization of hazmat traffic, which may be sufficient for some HMCFS objectives.
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From page 119...
... E.3 Representative Sample Scheduling With representative sampling, the data collection locations are selected to represent major types of hazmat transport corridors in the community. For example, data collection might be conducted at one location on an Interstate, one location on a bypass loop, one location on a major urban arterial, and one location at a downtown intersection of primary roads.
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From page 120...
... E.5 Stratified and Proportional Sample Scheduling Both stratified and proportional samples require prior knowledge of the sampled population to determine the required data collection parameters. For example, previous data on traffic counts might be used to identify average expected traffic levels on a daily basis at key transportation network locations.
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From page 121...
... Local entities whose HMCFS requires random sampling may consider asking a transportation professional, consultant, university faculty member, or other person with statistical training in traffic analysis for assistance with sampling design. E.7 Census A complete census of all traffic on a transportation network is nearly impossible to obtain without automated data collection procedures such as tag readers or video-based systems that collect data about vehicle locations and commodities carried.
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Key Terms

  • traffic levels
  • hmcfs data
  • hazmat transport
  • sample scheduling
  • hazmat traffic

  • conduct truck
  • commodity flow
  • sample data
  • sampling procedures
  • proportional sample

  • collection procedures
  • volunteers conduct
  • convenience sample
  • conducting local
  • placard counts

  • sampling design
  • flow studies
  • local hazardous
  • statistical training
  • data collectors

  • observed traffic
  • materials commodity
  • hmcfs requires
  • university faculty
  • traffic analysis

  • expected traffic
  • local entities
  • transportation professional
  • proportional sampling
  • hazardous materials


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