Assessing Longitudinal Arterial Performance and Traffic Signal Retiming Outcomes

Abstract

Agencies often find it difficult to justify investments in active traffic management. Historically, it has been a challenge to obtain data that would help make the case for those investments. While new data sources have emerged recently, there remains very little documentation of the potential long term benefits from signal retiming using associated performance measures. This study presents a use case for an active traffic management strategy on a signalized corridor over a 5-year period, during which traffic volumes increased by approximately 36%, and offset optimization was performed every 2-3 years. Despite the considerable volume growth, arrivals on green were increased by more than 41%, and the percentage of vehicles arriving on green increased by 10%, a gain of 6 percentage points. Furthermore, drivers experienced an average of 5% reduction in travel time and travel time reliability costs after each optimization. This resulted in a total user benefit over the 5-year period of approximately $3.6 million. Agencies can utilize these strategies to quantitatively assess how traffic performance and signal timing degrade over time, in a manner similar to physical infrastructure assets. The results highlight the benefits and associated business case of adopting a long-term active traffic management strategy, based on datadriven performance monitoring and decision making.

Economic Development Impact of Corridor Improvements

“…The first case study is located in Palm Beach, Florida as reported by Cambridge Systematics (2014). The second case study, located in Hamilton County, Indiana was reported in Lavrenz et al (2016). Both Cambridge Systematics (2014) and Lavrenz et al (2016) are the main sources of the inputs for these applications in TOPS-EIA.…”

“…One of the primary objectives of the signal optimization project was to maximize the arrivals on green. Weekday traffic data was collected during three weeks in June before the optimization and one week in July after the optimization, 6 a.m. to 9 p.m. in 2010, as reported in Lavrenz et al (2016). The traffic signals studied in this analysis are operated under traffic actuated control.…”

“…Data was collected from eight traffic signals. Table 5.3 summarizes the data retrieved from Lavrenz et al (2016) and entered in TOPS-EIA. The inputs were retrieved for a specific time of day (i.e., analysis period) before and after the first intervention in 2010.…”

“…Similarly, the default values for the valuation of benefits in TOPS-EIA were replaced by inputs from Lavrenz et al (2016). These inputs are shown in Tables 5.4 and 5.5.…”

“…Link volume is the average traffic volume on this segment of SR 37 over the chosen analysis period. The change in speed after applying the time of day plan that maximizes vehicle arrivals on green for the chosen analysis period was estimated to be 6.8% based on data from Lavrenz et al (2016). The default value for link capacity provided in the tool was used.…”