The RT3® is designed to reflect a small vehicle cornering at all times as the measuring wheel travels across the surface. We achieve this by measuring lateral friction applied to a load sensor by adding a small toe in angle to the measuring wheel(s). The GEM hub sensor measures the lateral force on that tire as it moves across the surface.

On a high friction surface, the corresponding Mu Value is higher. On a low friction surface, the Mu value will be much lower. We use a scale between 0-1.

With such a small wheel angle, the RT3® can run without a water system year round without significant degradation to the tire. If more wheel angle is required, that can be accommodated by the RT3® design, but the tire might build up heat which will change the properties of the rubber compound.

Understanding the parameters of the testing process and working to eliminate all variables outside of those you want to test is critical to understanding the true friction value of that tire running on that surface in those conditions. While we would like measuring friction to be simple topic, sometimes it can be a four dimensional problem to solve.


We call the sensor system we use the GEM Hub.

It is a stainless steel, multi-sealed fully enclosed system that protects a single high resolution load cell that is placed in the axial force measuring direction. We have no exposed chains, belts or pulleys.The GEM hub’s design protects the load cell from overload. The force signal is amplified at the hub and sent to the RT3® display or control panel.

Through the display we track the friction value, distance & speed. If a steering potentiometer is added to the vehicle, steering angle is also tracked.

The GEM hub has very few moving parts. It has proved to be extremely reliable with over multiple years of continuous use.


  • High repeatability and accuracy, generating a detailed picture of the surface conditions.
  • With a small toe-in angle, the RT3® test tires remain at normal temperatures during testing.
  • The measuring wheel can last up to 3,000 miles without replacement.
  • Toe-in angle can be increased from 0.5 to 8 degrees on the RT3® Curve.
  • For tire performance analysis, the camber of the tire can be changed.
  • The RT3® units can be used with any standard vehicle tire.
  • The RT3® Curve can accommodate tires with 216mm sidewall width and 850mm diameter.
  • There is a constant vertical load ensuring contact of the measuring tire to the surface.
  • The measuring wheels retract when not testing to minimize wear and tear on the test tires.

Our engineers love a challenge.

If we are not accommodating a specification that you require with our equipment, call us.

You will be amazed at the modifications we are making to our equipment to meet the specific needs of our customer base.


Halliday Technologies is committed to promoting environmental sustainability.

We choose each product in the manufacturing process to be durable. Ensuring the RT3® is built to last, we can drive down life cycle costs for our customers. Additionally, through objective and reliable data, our customers can reduce their chemical and salt usage during winter events by optimizing their treatment approach.