Forty-three years ago when I joined the Transportation and Traffic Engineering Industry (which makes me sound old – I know some of you are saying, well, Wes, you are), data collection – the art of counting cars – was entirely different as it relates to technology.
In 1972, turning movement traffic counts were conducted by having an individual sit on the side of the road in a lawn chair with a clipboard counting the number of cars that passed a particular site, turned right, left, or went straight. Shortly thereafter, the “clickers” came into play, which made one’s job that much easier. Then, turning movement counts became far easier for traffic counters/enumerators because entire “clicker boards” came into fashion where all of the movements could be counted at once.
Now, that was a fairly simple task if you had a roadway with 3,000 to 5,000 cars a day. However, roadways carrying 30,000, 40,000, 50,000 or more cars a day using even a 16 or 20-bank clicker, was a near impossible challenge. Clearly, data was not going to be anywhere near as accurate as it is today when one, two, or three persons were trying to count all of the cars visually, by hand.
Today, technology has advanced and traffic counting has not only become an art, but a true science. We utilize video technology and proprietary software that physically counts the cars, tracks the cars, and determines the classification of the vehicles. It doesn’t stop there – we can also count pedestrians, determining whether they are children or adults crossing at intersections or headed in a particular direction.
With the new camera detection, traffic signals not only determine cars that are waiting at a traffic signal to pass through the intersection safely or to extend the green time, but they also have the ability to count cars and to determine the number of persons that are occupying the vehicle, termed vehicle occupancy.
As it relates to “road tube counters” – devices that determine hourly and daily traffic volume along a section of a roadway (between intersections) – the original traffic counting machines were powered by 12-volt car batteries and were 12–14 inches wide and 18–20 inches high. These machines weighed 30–40 pounds each. Today, technology is different. These same types of machines have lithium batteries that can last for months without recharging and some machines are the size of your smart phone. We utilize laser technology and radar technology in many, many instances without the need for road tubes and we are able to determine the length of vehicles and the speed of vehicles and the lane that the vehicle is in, all with one machine on a tripod mounted 10–15 ft above the road surface.
What’s next? I can assure you: the days of the road tubes are numbered. It might even be that, before too long, data collection occurs by utilization of satellites in permanent orbit around Earth or the use of robots and drones.
Has technology changed since 1972? You bet it has! Is it going to change in the future? There is no doubt in my mind that this blog, when read 10 years from now, will be laughed at by traffic engineers and transportation planners because of the advances that have been made in traffic counting and data collection.