Section 2: Collecting and Posting Reliable Traffic DataAnchor: #i999492
Collecting Reliable Data
Traffic counters must accurately classify and count vehicles to yield reliable traffic data, vital to TxDOT’s roadway programs. Departmental traffic analysts exercise great effort to verify the accuracy of collected and reported counts by comparing the counts to historic traffic data. Traffic counters must precisely conduct manual classification counts whether in areas of high, medium, or low traffic flow. Counting an extra 15 minutes or undercounting can distort the count and render the data useless.
The traffic counter must set up at the specifically prescribed location. The traffic counter crew must count for exactly 24 consecutive hours. Occasionally, however, a 48-hour count may be necessary. The same counting precision is required for an extended count as for a 24-hour count. Counts are conducted Monday through Thursday only.Anchor: #i999507
Accurately Posting Data
Continued precision is extremely important as the traffic counter manually transfers hourly counts from the traffic recorder equipment to the required Form 1617A. Detailed instructions for completing Form 1617A are provided in Chapter 6 of this manual.