The purposes of this paper are to examine alternate classification systems of jobs, and to investigate how predicted volumes of employment-related trips vary according to the system used to classify jobs by type. The Southeast Michigan Council of Governments (SEMCOG) has obtained a special crosstabulation of 1990 census data on workers by traffic analysis zone of work. A method has been developed that uses industrial class and occupational class in conjunction to assign land use classes to the workers. This allows the linking of the workplace's land use class to the commuting trip characteristics (time of departure, trip duration, means of transportation) that are contained in the census crosstabulation. In addition, in 1994 SEMCOG conducted a household travel survey, that covered 7,400 households in Southeast Michigan. This survey included questions on the industrial class, and the land use class, of each employed person's primary job. These items are linkable to the characteristics of the home-to-work trip, including time of departure and arrival, means of transportation, and trip end locations, collected by the survey. The paper contrasts two systems of classifying kind of work or kind of job activity. One of these systems is industrial class, which related to the overall purpose of the business, agency, or governmental department. The other system is land use class, by which is meant the nature and characteristics of the activities, and usually also the buildings and associated open lands that the activities occupy, occurring at specific individual locations. SEMCOG's transportation modeling has used industrial class employment data because that was the best available. Now with a new wealth of tripmaking data by land use class employment, the performance of SEMCOG's transportation models may be significantly improved. Should the findings of these comparisons support the underlying assumption that employment by land use class, rather than by industrial class, is a better predictor of employment-related tripmaking, SEMCOG will investigate the feasibility of creating new trip generation equations.


  • English

Media Info

  • Pagination: 7p

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Filing Info

  • Accession Number: 00789766
  • Record Type: Publication
  • Files: NTL, TRIS, TRB
  • Created Date: Mar 10 2000 12:00AM