PHOTOLOG OF CALIFORNIA HIGHWAYS

A project is described in which 2 million 35 mm color slides have been linked together to form a 37-mile long film strip that covers every inch of 30,000 miles (15,000 each way) of state highways at 52 foot intervals. The slides which are individially computer-coded, cost 9-cents each. The photolog was made from a custom-fitted van in which was mounted a 35 mm Cine/pulse camera with an automatic exposure control. A photo-digital recording system, places 15 rows of binary-coded decimal numbers on the top quater of each frame, and a fifth wheel employing a "sulky" tire, measures distance and triggers the camera 100 times per mile. A Motion Analyzer projector is used for viewing purposes. All pictures are taken from the drivers vantage point. This shows all the traffic data inventory and natural elements in studying accident concentration or hazardous locations, and also provides the additional advantage of seeing all of them in their true spatial relationship. The average error is less than 0.5 percent. Shutter and speed combinations for acceptable photography are set forth. A 2-man crew works one week travelling 600 to 1000 linear miles driving at speeds of 65-70 mph. Data is logged on daily work schedules, standard district maps and in the State Highway Log. Photographs illustrate the equipment used and the storage of the photolog. The benefits of the system are listed. The usefulness of the system diminishes unless it is kept current. The costs of the photolog system are discussed and estimates are presented of the average savings. The system is considered to be particularly useful in this period of fuel shortage and economic crisis.

Media Info

  • Features: Photos; Tables;
  • Pagination: p. 20-23
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00262427
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 13 1974 12:00AM