1. What is traffic counting?
The City of St. Albert conducts annual traffic counting programs on Arterial roadways (moves traffic from local streets to freeways) and Collector roadways (moves traffic from local streets to arterial roadways) from May to October (weather permitting for the placement of traffic counting equipment). This program captures traffic volume and direction at mid-block locations.
This program uses Portable Pneumatic Road Tube Counters which are units that have rubber tubes that are placed across the travel lanes and use the pressure changes to record the number of axle movements.
2. How are locations chosen?
Locations are spread out across the city. An attempt is made to capture volumes at key locations. For example, a traffic counter would be placed on a Collector roadway near an Arterial roadway, as demand would be higher from the local roadways accessing these points.
The Engineering Department also receives input from residents who may have concerns at specific locations and the overall impact and efficiency on the roadway. If these locations are not scheduled for the annual program, special counts may be performed.
3. How does the City use this information?
Setups at each location are monitored for one week, and the traffic data is reported on an hourly basis (24 hours/7 days). An “Average Daily Volume” is calculated utilizing the sum of Daily Volumes (within 24 hour time frames) from Tuesday to Thursday. The average overall volume of these three days is the equivalent to “Average Daily Volume” expected on this roadway.
By comparison, the City recognizes annual growth and variances in traffic patterns and demands on the roadway systems. At intersecting roadways where volumes continue to increase, an upgrade may be required to the type of traffic control and further review may then be conducted.
4. What does the City look for in the traffic counts?
The goal of the traffic counting program has changed from simply recognizing traffic volumes to gathering additional information on St. Albert roadways. With the advancement of counting equipment, there is additional data such as vehicle speeds, vehicle classifications, vehicle gap periods (distances between vehicles) that may be collected. Not all setups are recording all information; however, at locations where speed or vehicle classification may be a perceived concern, the data may be collected and evidence action taken through the joint effort of the Engineering and Enforcement groups.
5. What improvements and adjustments have been made to the traffic counting program?
As technology has improved and has become more economical for implementation, the City of St. Albert has begun using traffic cameras at signalized intersections to perform traffic counts. The allows the cameras to capture traffic volumes for each movement at an intersection, which can then be used for future traffic signal timing adjustments. These units also monitor volumes throughout the entire year, and may have count zones broken down on a “per lane” basis. This provides the City with the ability to recognize traffic volume changes throughout the year and provides information on the impact that a loss of a single lane of travel may have on traffic flow.
As well, by using traffic cameras, it eliminates the risks to workers who would have to set up and maintain Pneumatic Road Tube Counters on high volume, higher speed arterial roadways.
2012 Arterial Roadway Average Daily Volume
2012 Collector Roadway Average Daily Volume