Regional Screenline Traffic Count

Agencies traditionally have placed a great deal of emphasis on the development and implementation of tools and methodologies for forecasting transportation demand and future highway performance through the use of travel demand models. However, the development of tools and databases to validate these models, based on actual existing transportation conditions (counts), has usually lagged behind.

The count databases that are available are typically old, include many estimates rather than recent hard data, and are often uncoordinated with local agencies. Also, there has not been a great deal of priority given to traffic counting efforts, perhaps because this is one of the easiest items to defer in terms of budget allocation and dedication of staff. Recognizing these long-standing issues, SCAG jointly with MTA initiated the Regional Screenline Traffic Count project to develop a comprehensive, defensible model validation screenline traffic count database for the Southern California region.

The main objectives for this project were identified as follows:

• Development of a regional screenline traffic count database system.
• Collection of existing available traffic counts from cities and agencies.
• Development of a framework for categorizing the screenline locations into similar groups.
• Estimation of the 2003 Annual Average Weekday Traffic (AAWT) counts.

Reports

• SCAG Screenline Traffic Count Final Report, June 2004
  • Appendix A - Freeway Annual Growth Factors
  • Appendix B - Tier 1 AAWT Adjustment Factors
  • Appendix C - Tier 2 & 3 Adjustment Factors
  • Appendix D - 24-Hour Machine Count Locations
  • Appendix E - Vehicle Classification Count Locations
  • Appendix F - Comparison of Caltrans 2002 Freeway Counts with 2003 AAWT
  • Appendix G - 2003 AAWT Counts
  • Appendix H - Annual Arterial Growth Factors
  • Appendix  I  - Tier 1 Truck Percentages
  • Appendix J  - Tier 2 & 3 Truck Percentages

Screenline Areas

• View Map of Regional Screenline Locations