Traffic Counter Comparison

Traffic Counter Comparisonon 2 Lane Roadways

Rubber Tube Temporary Counter Sites

VsWire Loop

Permanent Counter Sites

Rubber Tube Traffic CounterGamma Type Counter from TimeMark

Cost approximately $1000/deviceDiscounts for quantity purchases.

TimeMark Incorportated (800)-755-5882 FAX (503) 363-1716 www.timemarkinc.com

Rubber Tube CountAverage Weekday Count

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.

Two tubes allow counter to determine direction , speed, and classify of traffic.

Wire Loop Traffic CounterUnicorn Type from Diamond Traffic Products

Four wire loop option buried in asphalt

Diamond Traffic ProductsPO Box 145576433 Alder StreetOakridge Oregon 97463(541) 782-3903FAX (541) 782-2053

www.diamondtraffic.comE-mail: [email protected]

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 LayoutFour 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 CounterImportant to note what tube is plugged in to the A/B axle port.

Study Site on Route 53

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

2 - Lane Tube Type Site

0

20

40

60

80

100

120

0 1000 2000 3000 4000 5000 6000

Average Daily Traffic

Per

cen

t A

ccep

ted

Sig

nal

s

South

North

Rt 75 Rt 3 Rt 53

Route 75 Comparison12/16/2004

Northbound Lane

ADT 50% 85% Cars Trucks Big

2-lane 1076 33.9 39.3 865 166 44

1-lane 1080 33.7 39.2 797 236 47

Wire 1089

Southbound Lane

ADT 50% 85% Cars Trucks Big

2-lane 1062 32.3 37.7 746 261 48

1-lane 1053 32.0 37.1 772 235 45

Wire 1076

Total Lanes

ADT 50% 85% Cars Trucks Big

2-lane 2138 33.1 38.5 1611 427 92

1-lane 2133 32.9 38.2 1569 471 92

Wire 2165 33.1 38.8 1187 915 42

Route 3 ComparisonNote Speed of Wire Counter ??? Also short vehicle length ???

12/16/2004

Northbound Lane

ADT 50% 85% Cars Trucks Big

2-lane 1694 35.6 39.7 757 605 314

1-lane

Wire 1608

Southbound Lane

ADT 50% 85% Cars Trucks Big

2-lane 1761 36.0 40.4 1073 531 153

1-lane

Wire 1825

Total Lanes

ADT 50% 85% Cars Trucks Big

2-lane 3455 35.8 40.1 1830 1136 467

1-lane

Wire 3433 21.4 24.4 998 2302 133

Wire Loop Traffic Counter LayoutNote: 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 setup

also high 85% speed on Southbound 2-lane setup

12/16/2004

Northbound Lane

ADT 50% 85% Cars Trucks Big

2-lane 2549 31.7 37.3 1649 709 164

1-lane 2750 32.2 37.8 1720 857 172

Wire 2768

Southbound Lane

ADT 50% 85% Cars Trucks Big

2-lane 2279 36.5 78.0 1273 133 158

1-lane 2835 29.3 34.1 2134 541 159

Wire 2851

Total Lanes

ADT 50% 85% Cars Trucks Big

2-lane 4828 34.1 57.7 2922 842 322

1-lane 5585 30.8 36.0 3854 1398 331

Wire 5619 30.7 34.9 2822 2612 159

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 53Red car (southbound) high 85% speed, Pickup truck (northbound) data better. Traffic counter located in left ditch nearest to red car.

Errors Found in First Year of Operation of Permanent Wire Loop

Counter Sites

• 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).

Wire Loop Counter Rubber Tube Counter

End of Presentation

Thank You