Oregon DOT Study Evaluated Life Cycle Costs for Various Coordinated Intersection Signal Timing Systems and Vehicle Detection Technologies.
Oregon, United States
This study collected and analyzed event-based vehicle detection data from years 2015-2016 and from multiple technologies, including inductive loop, magnetometers, radar sensors, and video, thermal, and hybrid detectors, at four different sites in Oregon. The goal was to provide guidance for deployment of non-invasive detection for use in adaptive control, as well as develop a life cycle cost comparison of various detection sources. Data during fair weather from non-invasive detection zones co-located with inductive loops were compared based upon typical metrics used for driving adaptive algorithms, such as activations, occupancy, and time to gap out.
METHODOLOGY
In order to conduct a Life Cycle Cost Analysis (LCCA) for various vehicle detection and Adaptive Signal Control Technologies (ASCT) the initial step in obtaining cost data was reaching out to manufacturers and Oregon DOT (ODOT) officials through an informal survey. The second step was through direct email to the specific manufacturers and practitioners. A final attempt to capture pertinent cost information was made using national institution forums such as the Institute of Transportation Engineers (ITE). The LCCA results were obtained using an LCCA Tool developed for this study, and a three percent discount rate, ten-year analysis period, and a network of ten intersections. For signal control technologies, coordinated signal timing (CST) was included as a baseline measurement for the LCCA. Table 1 summarizes the cost estimates for a baseline CST system and four systems using different ASCT.
Table 1. Signal Control Technologies Cost Summary
Cost Component |
CST (Baseline) |
ASCT Type 1 |
ASCT Type 2 |
ASCT Type 3 |
ASCT Type 4 |
Initial Coordinated Signal Timing Cost Per Intersection |
$3,760 |
$20,000 |
$13,500 |
$10,000 |
$35,000 |
Additional Coordinated Costs per Intersection |
$0 |
$0* |
$0† |
$2,750 |
$0* |
Annual Coordinated Maintenance Cost |
$1,200 |
$17500/ # of intersections |
$0† |
$750 |
$0* |
Coordinated Server or Central Software Cost |
$0 |
$0* |
$20,000 |
$0 |
$0* |
Life Cycle Cost (10 intersections for 10 years) |
$139,962 |
$349,279 |
$335,000 |
$191,477 |
$350,000 |
* This cost is captured in initial cost. † This cost is captured in server cost.
Table 2 shows the life cycle cost of various vehicle detection technologies for one intersection over 10 years and Table 3 shows the cost breakdowns.
Table 2. Life Cycle Cost for Vehicle Detection for One Intersection Over 10 Years
Alternative |
Total Initial Costs |
Total Present Annual Costs |
Total Present Replacement Costs |
Life Cycle Cost |
Inductive Loop |
$20,400 |
$0 |
$0 |
$20,400 |
Magnetometers |
$31,750 |
$0 |
$4,629 |
$33,451 |
Radar |
$46,520 |
$38,949 |
$0 |
$85,469 |
Video Stop Bar |
$42,000 |
$35,255 |
$0 |
$77,255 |
Thermal |
$51,984 |
$20,327 |
$0 |
$72,311 |
Hybrid (video + radar) |
$31,520 |
$24,880 |
$0 |
$56,400 |
Table 3. Vehicle Detection Technologies Cost Breakdown
|
Inductive Loop |
Magnetometers |
Radar |
Video Stop Bar |
Thermal |
Hybrid (video + radar) |
Detector Purchase |
$600 |
$550 |
Stop Bar Detection: $5,000; Advanced Detection: $5,950 |
$3,000 |
$3,538 |
$5,880 |
Detection Channels |
$150 / card |
$525/card |
Stop Bar Detection:$350/card; Advanced Detection: $330 / card |
Stop Bar: $3,000; Advanced:$1,500 |
Stop Bar: $4,010; Advanced: $2,610 |
$1,000 |
Other Costs |
|
$5000 / Intersection |
|
|
|
|
Major Stop bar Detectors / Approach Detection Cost |
$4,800 for 7 detectors |
$6,150 for 7 detectors |
$5,350 |
$6,000 |
|
$6,880 |
Minor Stop bar Detectors / Approach Detection Cost |
$2,700 for 4 detectors |
$3,975 for 4 detectors |
$5,330 |
$6,000 |
|
$6,880 |
Major Advanced Detectors / Approach Detection Cost |
$1,350 for 2 detectors |
$2,875 for 2 detectors |
$6,280 |
$4,500 |
|
$1,000 |
Minor Advanced Detectors / Approach Detection Cost |
$1,350 for 2 detectors |
$2,875 for 2 detectors |
$6,280 |
$4,500 |
|
$1,000 |
Estimated Lifespan of Detection |
15 years |
8.5 years |
10 years |
10 years |
10 years |
10 years |
Annual Maintenance Visits / Cost per Approach |
0 |
|
$133.25 |
$158.25 |
$158.25 |
$291.67 |
Traffic Control Maintenance / Cost per Approach (1 lane) |
0 |
$437.50 |
$437.50 |
$437.50 |
$437.50 |
$437.50 |
Improving Adaptive/Responsive Signal Control Performance: Implications of Non-Invasive Detection and Legacy Timing Practices
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