About the Map

Welcome to H-GAC's Transportation Department's Interactive Traffic Count Website. This site displays traffic counts provided to H-GAC by the Texas Department of Transportation (TXDOT) for our eight county planning area.

TxDOT Saturation Counts

Saturation counts are made available to the public every 5 years. They represent the maximum number of counts collected for an urban area. The counts are 24 hour weekday (Monday thru Thursday) axles divided by two. These count locations consist of static station points positioned throughout the Houston-Galveston urban areas with count values from the 2006 and 2012 saturation count program. In this application, rolling your mouse over the icon will show the elements shown in the figure (location, zip code, 2006 and 2001 volume data). However, both year count values can be viewed side by side (2006) and (2012) along with TxDOT's assigned Station Location Number in database table only.

Vehicle Classification Data Collection

TxDOT’s Transportation Planning and Programming Division makes vehicle classification counts at 650 to 750 locations across the state each year. (To see a map of TxDOT districts, visit http://www.dot.state.tx.us/local_information/default.htm. The number of sites counted each year varies according to the condition of the road counting hardware installed at the sites to collect the data with automated vehicle classifier (AVC) equipment. The number of special requests for vehicle classification counts also affects the number of sites. At AVC sites, TxDOT has sensors and a loop embedded in the roadway with a cabinet on a pedestal to house the electronics, loop, and piezo sensor leads. If there are problems at the site (construction, bad sensors, or loops), TxDOT must either repair the equipment or schedule a visual classification contract to collect the data. At locations where there is no stop-and-go traffic, TxDOT may choose to collect vehicle classification data with road tubes.

There are three types of vehicle classification data collection:

• Automatic Vehicle Classifer(AVC) equipment at approximately 250 sites with 48-hour data collection.
• Contract visual classification counts at approximately 400 sites with 24-hour data collection.
• Telemetry (AVC) at 25 border sites with data collection 365 days a year. TxDOT makes the counts using the currently installed equipment. Where equipment is not available or not suitable, contractors make visual classification counts.

TxDOT makes the counts using the currently installed equipment. Where equipment is not available or not suitable, contractors make visual classification counts. Counts consist of 24-hour samples (midnight to midnight) that categorize vehicle types into 13 classes and unclassified.