00978591

Component

https://doi.org/10.3141/1870-18

http://scholar.google.com...eson&publication_year=2004

The accuracy and precision of five common portable speed measurement systems were evaluated in a controlled field evaluation. The following systems were evaluated: traffic classifier with pneumatic tubes, traffic classifier with piezoelectric sensors, tape switches, radar, and lidar (i.e., police laser). A test vehicle with a calibrated Nitestar distance-measuring instrument (DMI) made 100 passes through the test site at two speed levels (50 passes at 55 mph, 50 passes at 35 mph), and speed was recorded by each device for each pass. DMI speed was deemed the true speed for each pass, and deviations from the DMI speed for a given device were considered errors. Paired t-tests were performed on the speed data measured by each device versus the DMI. The following conclusions were drawn: (a) All devices performed equally well for the 35-mph trials. (b) Lidar and radar were the most accurate and precise devices for the 55-mph trials. (c) For all devices, any errors that occurred for a single speed measurement were relatively small (less than +/- 1.5 mph). (d) With the exception of radar, all devices were slightly less accurate and less precise at higher speeds. (e) There was little difference in performance between on-pavement devices (i.e., tubes, piezoelectric sensors, and tape switches). (f) Inaccuracies observed in on-pavement equipment likely were caused by slight measurement errors during placement of the sensors or movement of the sensors resulting from repeated tire hits. Because all devices were relatively accurate, the researchers recommended that portable speed measurement equipment be selected to suit the characteristics of a given data collection situation.

This paper appears in Transportation Research Record No. 1870, Data and Information Technology.

00978573

English

p. 139-146

2004

Transportation Research Record

030909464X

Figures (5) ; Photos (3) ; References (3) ; Tables (5)

Accuracy; Distance measuring equipment; Errors; Field tests; Laser radar; Performance; Portable equipment; Precision; Radar; Speed data; Speed measurement; T test

Tape switches; Traffic classifiers with piezoelectric sensors; Traffic classifiers with pneumatic tubes

Highways; Operations and Traffic Management; Planning and Forecasting; I72: Traffic and Transport Planning

TRIS, TRB, ATRI

Sep 29 2004 12:00AM

• APPLICATION OF REGRESSION ANALYSIS FOR IDENTIFYING FACTORS THAT AFFECT SEASONAL TRAFFIC FLUCTUATIONS IN SOUTHEAST FLORIDA
• COMPARISON OF COMMODITY FLOW FORECASTING TECHNIQUES IN MONTANA
• DATA PARTNERING BETWEEN TRANSPORTATION AGENCIES FOR MUTUAL BENEFIT: THE ILLINOIS EXPERIENCE
• DEFINING AND MEASURING TRAFFIC DATA QUALITY: WHITE PAPER ON RECOMMENDED APPROACHES
• DEVELOPMENT OF A JAVA APPLET FOR GENERATING TRUCK TRIPS FROM FREIGHT DATA
• EIGHTY WEEKS OF GLOBAL POSITIONING SYSTEM TRACES: APPROACHES TO ENRICHING TRIP INFORMATION
• ENHANCEMENT OF VEHICLE SPEED ESTIMATION WITH SINGLE LOOP DETECTORS
• ESTIMATING ELIGIBILITY RATES: CRUCIAL COMPONENT OF THE CALCULATION FOR RESPONSE RATES
• ESTIMATING SPATIAL MEASURES OF ROADWAY NETWORK USAGE FROM REMOTELY SENSED DATA
• INVESTIGATING EFFECTS OF CORRELATED SERVICE TIMES ON SYSTEM PERFORMANCE: IMPLICATIONS IN BORDER CROSSING OPERATIONS
• INVESTIGATION OF DYNAMIC PROBE SAMPLE REQUIREMENTS FOR TRAFFIC CONDITION MONITORING
• LOOP DETECTOR DATA DIAGNOSTICS BASED ON CONSERVATION-OF-VEHICLES PRINCIPLE
• MONTE CARLO SIMULATION OF HOUSEHOLD TRAVEL SURVEY DATA FOR SYDNEY, AUSTRALIA: BAYESIAN UPDATING USING DIFFERENT LOCAL SAMPLE SIZES
• PAVEMENT SMOOTHNESS AT WEIGH-IN-MOTION SITES: DEVELOPING SPECIFICATIONS FOR THE LONG-TERM PAVEMENT PERFORMANCE PROGRAM
• RULES FOR ASSESSING DATA QUALITY OF ACTIVITY-SCHEDULING SURVEY RESPONDENTS
• STATISTICAL METHODS FOR DETECTING SPATIAL CONFIGURATION ERRORS IN TRAFFIC SURVEILLANCE SENSORS
• TRANSIT BUSES AS TRAFFIC PROBES: USE OF GEOLOCATION DATA FOR EMPIRICAL EVALUATION
• USE OF AUTOMATIC POSITION REPORTING SYSTEM DATA FOR ENHANCING TRANSPORTATION PLANNING OPERATIONS
• USING BUS TRAVEL TIME DATA TO ESTIMATE TRAVEL TIMES ON URBAN CORRIDORS
• USING FLOATING CARS TO MEASURE TRAVEL TIME DELAY: HOW ACCURATE IS THE METHOD?