In-field Qualitative Assessment. The Engineer will perform an in-field qualitative assessment of the existing signal operation. This will specifically include the existing cycle lengths, splits, phase sequences, and modes of left turn protection. During this assessment, the Engineer will also identify the intersection approaches where excessive queuing is observed and/or where capacity appears to be substantially constrained. One extremely important step in the assessment will be the determination of the appropriate signal progression speeds. Such speeds cannot be accurately determined just by inspecting the results of floating car studies. This is because the actual speeds when the before travel time runs are made will be heavily influenced by adversities that the subsequent timing improvements may correct. As such, the determination of appropriate progression speeds will be made by an experienced signal timing engineer.
