Experience from the deployment of ACS Lite in Ohio.
Gahanna, Ohio, United States
Adaptive Control Software - LITE: Before and After Traffic Analysis Report, Hamilton, City of Gahanna, Ohio
Summary Information
The FHWA performed a "before" and "after" traffic data collection study to assess the benefits of Adaptive Control Software Lite (ACS Lite). The site selected for this study was a 1.4 mile section of the Hamilton Road Corridor located in Gahanna, a city in the Columbus metropolitan area. Data was collected at nine intersections along the corridor before and after the ACS Lite software was implemented. "Before" data was collected over a four day period during a typical work week, while the "after" data was collected over a three day period a few weeks later.
Methodology:
- Volume counts were collected in 15-minute increments pneumatic tubes and machine software. These volumes were then used to assess any changes in traffic patterns during the before and after study periods.
- Speed and travel time data was collected utilizing the "floating car" methodology, where a test vehicle drove through the arterial, allowing its speed to be dictated by the platoon speed, and not necessarily the speed limit. Travel time measurements began when the test vehicle passed the stop line at the first intersection and ended when the vehicle passed the stop line at the last intersection in the section of the arterial being evaluated.
- Statistical analysis was performed on the "before" and "after" data for comparison.
Findings:
As shown in the table below, with the implementation of ACS Lite, the mean speed, median speed, and the 85th percentile speed increased by 1 percent, 1.4 percent, and 4 percent.
Statistic |
Before |
After |
---|---|---|
Number of Observations |
123 |
121 |
Mean Speed (mph) |
20.8 |
21.0 |
Median Speed (mph) |
21.0 |
21.3 |
Standard Deviation |
3.9 |
4.7 |
Range (mph) |
10.9 - 35.3 |
10.2 - 34.7 |
Skew |
0.33 |
0.37 |
85th Percentile Speed (mph) |
23.0 |
24.0 |
The benefits analysis, analyzing total delay, number of stops and fuel consumption, indicates that based on the data collected, there would be annual savings of $88,400 due to operational improvements derived from the ACS
Lite technology.
Before (per veh) | After (per veh) | Savings (per veh) | Peak Hours (all vehs) | Peak Hour Savings | |
Total Delay (hr) | 0.03761 | 0.03758 | 0.00003 | 0.15588 | $1.89 |
Total Stops | 3.5 | 2.9 | 0.6 | 3117.6 | $43.65 |
Fuel (gallons) | 0.103 | 0.098 | 0.004 | 23.590 | $53.08 |
Peak Hour Benefits | $98.61 | ||||
Daily Benefit | $340.03 | ||||
Annual | $88,408.69 |
Peak hours = average savings *(average corridor peak hour volume*4 peak hours