The report presented methodology for comparing arterial corridors in terms of mobility-based performance measures, with the goal of establishing a process for easily identifying corridors in need of signal re-timing or adaptive signal control.
The evaluation first identified the number of "abnormal" traffic days in a year to characterize the cost-effectiveness of an adaptive system. Then, for "normal" days, it compared volume-normalized performance among corridors to identify problematic segments. This analysis was performed for a total of 13 arterial corridors: 12 around Des Moines, and 1 in Omaha.
The study methodology identified three corridors with high numbers of "anomalous" days, and three that performed poorly on "normal" days.
Researchers characterized the analysis used as "extensible," and considered the available performance metrics from the data to be both "flexible and robust" in accurately identifying problematic corridors.
The study suggested that its methods may be expanded to cost-benefit analyses, to identify agency priorities for arterial improvements, or to effectively automate the process of screening locations for signal re-timing.
Though dollar amounts were not given, as the data used had already been purchased by the Iowa DOT the cost savings incurred by not purchasing and installing field infrastructure were indicated to be considerable.