2011 Traffic Data Report for New York State
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2011 TRAFFIC DATA REPORT FOR NEW YORK STATE - Table of Contents Page Chapter 1: Introduction .........................................................................................................1 Chapter 2: Traffic Data Collecting Program Overview ........................................................2 Chapter 3: Accuracy of Traffic Data Section 3.1 Data Collection Equipment Requirements .............................................3 Section 3.2 Data Quality Control Checks .................................................................4 Chapter 4: Continuous Count Program Section 4.1 Introduction ............................................................................................7 Section 4.2 Maps of Continuous Count Sites ..........................................................8 Section 4.3 Traffic Monitoring Site Details and Specifications ..............................32 Chapter 5: Coverage Count Program Section 5.1 Volume, Speed and Classification Counts ............................................33 Section 5.2 Highway Performance Monitoring System ..........................................36 Section 5.3 Annual Traffic Monitoring Workshop ..................................................36 Section 5.4 Mobile Traffic Monitoring Platforms ...................................................37 Section 5.5 County Counter Initiative .....................................................................38 Chapter 6: Adjustment Factors Section 6.1 Seasonal (Monthly) Adjustment Factors ..............................................39 Section 6.2 Axle Adjustment Factors ......................................................................41 Section 6.3 Example of Estimation of AADT .........................................................43 Section 6.4 Heavy Vehicle Percentages...................................................................45 Chapter 7: Traffic Data Viewer ...........................................................................................46 Chapter 8: Traffic Growth Forecasting and Estimation Techniques ...................................47 Appendix A: New York State Reference (900 Series) Routes Appendix B: New York Parkways by Jurisdiction Appendix C: AADT Values for Select Toll Facilities Appendix D: NYSDOT Regions and County Codes Appendix E: Continuous Count Sites by Factor Group Appendix F: Traffic Volume Report 0 - Chapter 1 Introduction The Highway Data Services Bureau is responsible for collecting and reporting highway data in New York State. The authority for the bureau to take traffic counts on public highways throughout New York State is provided by the: Laws of New York State Book 24 (Highway Law) Part I Article II (Commissioner of Transportation) Section 10 (General powers and duties of the Commissioner relating to highways) Paragraph 13 - (“The commissioner of transportation shall :...) Compile statistics relating to the public highways throughout the state, and collect such information in regards thereto as he shall deem expedient.” This work is undertaken in cooperation with the United States Department of Transportation, local governments and other New York State departments and agencies. The United States Department of Transportation provides financial assistance for this activity. The NYSDOT Traffic Monitoring System complies with AASHTO Guidelines for Traffic Data Program (1992), FHWA Traffic Monitoring Guide (2001), and United State Code 23 CFR 500 B whose purpose is to “set forth requirements for development, establishment, implementation, and continued operation of a traffic monitoring system for highways and public transportation facilities and equipment (TMS) in each state.” Questions, comments and suggestions, contact: NYSDOT Highway Data Services Bureau Traffic Monitoring Section 50 Wolf Road, POD 3-2 Albany, New York 12232 (518) 457-1965 [email protected] Traffic data is available on the Highway Data Services Bureau’s web page: https://www.dot.ny.gov/divisions/engineering/technical-services/highway-data-services 1 Chapter 2 Traffic Data Collection Program Overview Chapter 2 Traffic Data Collection Program Overview The New York State Department of Transportation collects, summarizes and interprets information on the traffic traveling the State's highway system. The data is used to assess transportation needs and system performance as well as to develop highway planning and programming recommendations. Traffic data is also important for route planning and in the design of highway projects. Other government agencies and private businesses also employ this information. To collect this information, the Department operates two traffic monitoring systems: 1. A Statewide Traffic Monitoring System currently consisting of 176 permanent continuous count stations that collect volume, speed, vehicle classification and weigh-in-motion data 24 hours per day, 365 days per year. These sites are located throughout the State to monitor overall traffic trends. Information from these counters is used to determine traffic growth and tendencies as well as develop pavement design input, seasonal adjustment factors used in determining estimates of annual average daily traffic (AADT) and directional design hour volumes (DDHV). 2. A portable traffic counter program, also known as short counts, is comprised of inventory counts taken on the Federal and State highway systems, along with county and town roads. Special counts, including ramp, approach and turning movement counts, are taken for specific State projects. In total, approximately 12,000 counts of 2-7 days duration are taken annually. The State Touring Route System alone is divided into approximately 8,200 traffic control sections. As part of the inventory count program, each section is generally counted once every 3 years. The annual inventory program consists of 3,000+ counts obtained on the State Touring Route System and another 9,000+ counts taken for other purposes such as sampling of off system Federal Aid eligible and non-Federal Aid eligible local facilities, county roads, off system bridge counts, at-grade railroad crossing counts, and other samples to support the Federal Highway Performance Monitoring System. Results are used to determine Vehicle Miles Traveled (VMT) and to develop growth factors for estimating current year counts from known prior year counts. Vehicle classification counts obtained at approximately 4,400 of the 8,200 count locations are used to develop NYSDOT regional axle adjustment factors. Individual vehicles are assigned to one of thirteen vehicle type categories established by the Federal Highway Administration (FHWA). Axle adjustment factors are computed for each highway functional classification category in each NYSDOT Region. Limited speed data is also collected during vehicle classification counts. 2 Chapter 3 Accuracy of Traffic Data Chapter 3 Accuracy of Traffic Data Section 3.1 Data Collection Equipment Requirements Data collection equipment in use by NYSDOT and/or data collection contractors adheres to the following accuracy requirements: • All portable traffic counters are tested annually, prior to the count season, to ensure that the count deviation does not exceed 2% from the average of the counters tested. • The average error in the speed of vehicles recorded is 2 km/h (1 mph) or less. Compliance is determined through simultaneous measurement of individual vehicle speeds using radar or previously tested equipment. • Vehicle type classification errors may not exceed 10% of the actual volume in any classification study conducted in a multi lane configuration. Vehicle type classification errors may not exceed 5% of the actual volume in any classification study conducted in a single lane configuration. • When there are fewer than one hundred (100) vehicles in a class, an error equal to the square root of the actual number of vehicles is deemed acceptable. Errors are computed based upon the sum of the absolute differences between the recorded and true volumes in each classification. The true value of each classification is determined by simultaneous manual observation for a period of one hour. • A Weight In Motion (WIM) Automatic Continuous Traffic Recorder (ATR) weighs and classifies vehicles and/or vehicle combinations having up to thirteen (13) axles using the input from Class I piezoelectric axle sensors and determines the weight of each axle and the speed of the vehicle in accordance with ASTM standard E1318-02; TYPE I: Tolerance for 95% probability of conformity: Wheel Load ±25% Axle Load ±20% Axle Group Load ±15% Gross Vehicle Weight ±10% Speed ±2 km/h (± 1 mph) Axle Spacing ±150 mm (± 0.5 ft.) 3 Chapter 3 Accuracy of Traffic Data Section 3.2 Data Quality Control Checks The following are typical checks performed by traffic monitoring personnel in the review and editing of traffic data, using either a manual procedure or the automatic checks set in the NYSDOT Traffic Count Editor (TCE), and polling (telemetry) software. If the checks reveal data that is suspect, further investigation must be conducted to determine if the data is faulty and what course of action is mandated; i.e. deletion of a bad interval, repair of faulty equipment or discard the entire count. All Count Types All lanes and directions for one station must be processed, edited and submitted at the same time. Counts should contain distinct AM and PM peaks that can be easily verified graphically. Peak hour zero search – Typically there should be no hourly intervals with zero vehicles during the AM