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Traffic Counter Comparison on 2 Lane Roadways. Rubber Tube Temporary Counter Sites Vs Wire Loop Permanent Counter Sites. Rubber Tube Traffic Counter Gamma Type Counter from TimeMark. Cost approximately $1000/device Discounts for quantity purchases. TimeMark Incorportated
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Traffic Counter Comparisonon 2 Lane Roadways Rubber Tube Temporary Counter Sites Vs Wire Loop Permanent Counter Sites
Rubber Tube Traffic CounterGamma Type Counter from TimeMark Cost approximately $1000/device Discounts for quantity purchases. TimeMark Incorportated (800)-755-5882 FAX (503) 363-1716 www.timemarkinc.com
Rubber Tube CountAverage Weekday Count Two tubes allow counter to determine direction , speed, and classify of traffic. Installed for 1-3 days (Tuesday-Thursday) to determine average weekday traffic. Average weekday traffic then adjusted to average yearly daily traffic by seasonal adjustment factors.
Wire Loop Traffic CounterUnicorn Type from Diamond Traffic Products Four wire loop option buried in asphalt Diamond Traffic Products PO Box 1455 76433 Alder Street Oakridge Oregon 97463 (541) 782-3903 FAX (541) 782-2053 www.diamondtraffic.com E-mail: diamondtrf@aol.com
Typical Permanent Site Cost $28,000 for 4 sites with software included. Constructed by tribal construction department with aid of electrician to set meter base and connect to local power grid.
Traffic Counter Loop Layout Four Loops allow counter to determine lane volumes, speed and length of vehicle.
Type Counter Layouts Studied • Double Lane Rubber Tubes (two tubes 16’ spacing crossing entire road. IE both lanes) • Single Lane Rubber Tubes (two tubes 16’ spacing each lane. IE anchored in center of road with PK type nails) • Wire Loop Counter Sites (4 Detectors – 2 each Lane 16’ spacing between loops in lanes )
Typical Study Site Three Rubber Tube Counters and One Wire Loop Counter Important to note what tube is plugged in to the A/B axle port.
Good ?? Data • Route 3 • Rubber tubes cover both lanes of traffic. • Axle A 94% used • Axle B 88% used • 3455 ADT
Bad Data (High Error Percent) • Route 53 • Rubber tubes cover both lanes of traffic. • Axle A 69% used • Axle B 88% used • 4828 ADT
Percent Accepted Signals 2-Lane Tube Type Counters Rt 75 Rt 3 Rt 53
Route 3 ComparisonNote Speed of Wire Counter ??? Also short vehicle length ???
Wire Loop Traffic Counter Layout Note: 16 foot loop spacing, not 10 foot Corrected 1/6/05
Typical Speed Distribution (Good Day)12-16-04 Northbound Speed Distribution (Uphill) Southbound Speed Distribution (Downhill)
Typical Speed Distribution (Bad Day)12-28-04 Northbound Speed Distribution (Uphill) Note: Loss of contact of one loop @ 4:00 am due to poor electrical connection. Repaired on 1/6/05. One Loop (two wires) were not crimped to connector in cabinet by contractor. Southbound Speed Distribution (Downhill)
Route 53 ComparisonNote: Low Counts on 2-lane rubber tube setupalso high 85% speed on Southbound 2-lane setup
Note: Many counts in the +55 mph class due to echo of signal in tube? and/or high traffic volume and high % error signals for one tube. This is the one site that used “D” type tubing for counter. This tubing may be the cause of the high speeds and high error %.
2 Lane Study Site on Route 53 Red car (southbound) high 85% speed, Pickup truck (northbound) data better. Traffic counter located in left ditch nearest to red car.
Loose connections between wire loops and counter. This produced low ADT counts on random days. Programmed wrong spacing between loops in lane. This produced bad speed and length data all the time. High axle signal error percentage in high volume site with tubes installed across both lanes of traffic. This produced bad speed records for one lane and low ADT counts all the time for one direction (southbound lane). Errors Found in First Year of Operation of Permanent Wire Loop Counter Sites Wire Loop Counter Rubber Tube Counter
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