Section 4: Accumulative Count Recorder Traffic Data
Anchor: #i1104892ACR Data Collection
ACR data collection includes short-term traffic volume counts. TPP makes or contracts out between 60,000 and 80,000 counts each year. TPP performs counts on Highway Performance Monitoring System (HPMS) samples and on-system roads annually and off-system counts on county roads and in urbanized areas on five-year cycles. TPP determines annual count locations and contractors perform the counts. Contractor acquisition of special counts such as turning movements and vehicle classification may begin in FY2000. Additional manual counts may be requested by TxDOT district offices by submitting a request form to TPP.
Anchor: #i1104905ACR Data Analysis
Accumulative count recorders collect data in 24-hour samples that include all axles passing a point. TPP uses counted or estimated vehicle classification data at locations to determine the axle-to-vehicle ratio for each axle count. ACR-recorded count volumes are converted into total number of vehicles using these ratios.
Anchor: #i1104915ACR Data Reporting
Typically, TPP maintains ten years worth of historic data to provide background information. Anyone who needs traffic data may obtain information from TPP -Traffic or TPP - Data Management.