Experience with Sydney Coordinated Adaptive Traffic Systems (SCATS) in Oakland County, Michigan.
Detroit, Michigan, United States
A Sydney Coordinated Adaptive Traffic System (SCATS) was initially deployed at 28 intersections and then expanded through Faster and Safer Travel through Traffic Routing and Advanced Controls (FAST-TRAC) to cover additional intersections in the northern metropolitan area of Detroit, Michigan. The design was intended to use roadside video cameras, computers, and communication networks to monitor traffic conditions and automatically adjust signal timing as needed to reduce vehicle stops, decrease delay, and improve traffic flow. Since the initial deployment, engineers have continued to fine tune its operational parameters to improve traffic conditions and increase safety.
SYSTEM COSTS
Cost data for SCATS and pre-timed signal systems were collected from the Road Commission for Oakland County (RCOC). While computing present worth cost and equivalent annual cost, a discount rate of four percent was considered. Present worth cost, equivalent annual cost and corridor cost per year per mile are presented in the table below as excerpted from the source report (2010).
| Attributes |
SCATS System
|
Pre-Timed
|
Difference in Cost
|
|---|---|---|---|
| Initial Cost |
$120,000
|
$100,000
|
$20,000
|
| Maintenance cost/year |
$9,000
|
$4,000
|
$5,000
|
| Life |
15 years
|
15 years
|
15 years
|
| Salvage |
0
|
0
|
0
|
| Discount Rate |
4%
|
4%
|
4%
|
| Present Worth of Cost |
$220,062
|
$144,472
|
$75,590
|
| Cost/Year |
$19,788
|
$12,990
|
$6,798
|
| Corridor cost/mile/year [1] |
$28,789
|
$19,412
|
$9,376
|
[1] = (Cost/year)*number of signals within corridor/Length of corridor in miles
Note: Length of SCATS and Pre-Timed corridors are 6.186 and 8.03 miles respectively.
Safety Evaluation of SCATS Control System: Final Report
SCATS implementation cost: - $19.8K per mile. SCATS annual maintenance cost: - $9K per mile.
