Traffic Data Field Operations

The Traffic Data Field Operations short duration traffic count season started March 1, 2007. From March through November, the Short Count Team will be setting traffic counters along 7,000 miles of Washington highways. Traffic counting is the process of monitoring vehicle traffic using electronic equipment or visual observation.

Electronic traffic counters with rubber tubes attached are strategically, hand placed to collect traffic volumes, traffic speed and vehicle types (classification) for 72 hours duration. Typically, counters are set on Monday morning and retrieved on Friday morning and physically monitored for accuracy once each day during the 72 hours. Each counter is programmed in the field by computer using vendor software. As vehicles drive over the tube, the traffic recorder enters the activation into its log for traffic volume, speed and classification.

While the electronic counters are monitoring traffic, the team also performs visual observations (manual) counts. This process is performed for turning movements and verification of the permanent traffic recorder sites equipment accuracy.

The data collected is used by a variety of customers including: the headquarters and region traffic, planning and design engineers, the Federal Highway Administration (FHWA), other state agencies, city, county and other public or private organizations.

The Infra-Red Traffic Logger (TIRTL) is being field tested at this time. The system consists of two instruments, a transmitter and a receiver, which are set on each side of the road to act as the sensors (replacement for rubber tubes) to record traffic. Using internal batteries the sensors will operate for approximately one week.

 

 

Two light beams across the road at axle height, measures axle break information to classify and count vehicles. Vehicle speed is measured by the time differential between each parallel light beam being broken by a vehicle axle. And vehicle lane classification is measured by the time differential between each parallel and cross light beam being broken.

WSDOT has the need to collect traffic data in high volume traffic and/or high hazard (red) zones. The benefits of this system are that they are non-intrusive (improving safety for the field crew during deployment) and hidden from traffic. This equipment is portable or can be installed in a fixed location and can be powered by batteries, solar panel or external electricity.

Transportation Data Office, Traffic Data Field Operations Counting Team

Front row Left to right: Ryan McBroom, John Hendrickson, Jesse Mills, Doug Blake, Tom Snaza
Back row left to right: Brooks Johnson, Chris Pottorff, Charles Johnson, Jeff Mydlar, Todd Breckel, Ryan Troupe, Matt Evans