Understanding the Data

Box that houses the IR counter

The Connecticut Trail Census facilitates the collection and utilization of the following two types of trail use and user data:

  1.  Use Count Data (# of uses)

    • Obtained through the use of infrared (IR) counters set up on each participating trail.
    • The counters have sensors that can detect a change in temperature passing by the counter.
    • Each time the sensor detects this temperature change, it registers this as a use.
  2. Intercept Survey Data (user behavior)

    • Collected by volunteers who conduct surveys intercepting trail users.
    • The survey consists of multiple choice and open ended questions on a variety of trail use topics such as distance traveled to use the trail, primary reason for using the trail, and demographic information about who is using the trail.

Understanding the Counter Data


Because the IR counters assume a use has occurred each time there is a change of temperature, these counts need to be adjusted to account for possible errors. Under-counts can occur if people traveling side by side, bikes pass the counter too fast, or simple mechanical error.

The method used to adjust the raw IR counter data uses volunteer conducted “manual counts”. To complete a manual count, the volunteer is situated within view of the IR counter and records the actual number of people who pass by the counter. Each site must complete at least 10 hours of manual counts over the course of the season. These manual count totals are compared to the number of uses registered by the IR counter and an adjustment factor is established.

Each year, manual counts continue to be completed and a more accurate adjustment factors will be established.

Use Vs. Trip

This count data shows number of uses or trips, not visits or visitors. Knowing that the IR counters register warm bodies passing by the IR scope, it can be assumed that trail users who travel out and return back, they will pass the counter twice and be counted twice. For trails with primarily out and back traffic, trail visits can be estimated at
½ of the count total.

Understanding the Intercept Survey Data

Number of surveys received by each site in 2017.

Statistical Caveats

The samples of volunteer conducted surveys may not be a representative sample of all multi-use trails in the state or of all multi-use trail users as a whole. This is because only a limited number of trails were able to participate for various reasons.

Another consideration should be made because trails were not selected to accurately represent particular typologies. Factors that influence a trail’s typology include urban versus rural setting, the total trail length, it’s permitted uses, surrounding population density, etc.

The fact that relatively few trails are represented by very large samples should be considered carefully in interpreting this data. The users intercepted also may not be representative because data collection times were limited for practical reasons like volunteer availability, weather, and likely use times.