Building a Traffic Video Observation Matrix

Short answer

An observation matrix is the written map of locations, approaches, movements, classes, intervals and outputs that analysts apply to a video study.

Before the project starts

• Start with the decision the data must support.
• Use a current site plan or unambiguous map reference.
• List each included movement and road-user category.

Practical approach

Make labels consistent between the site plan, source folder, workbook and final data. State exclusions and edge cases, including shared paths or partial visibility.

Checks and limitations

Walk through the matrix against a representative clip before production work begins.

A matrix cannot compensate for source footage that does not show its required observations.