Connects two shorter lengths of tube when you need more length. Splicers should not be positioned where they will be hit by traffic. They could be used, for example, to extend a tube across a median.
Total tube length should be no more than 75 feet (23 m). Air pulses that have to travel farther than that may be too weak to be recorded by the time they get to the counter. Pulses that are weaker to begin with, such as from slow traffic or small bicycle tires, will not even make it that far.
Be sure the sensor indicators on your counter are consistently triggered by hits in the far lane before starting a study. If not, try minimizing the length of tube between the counter and the road. Coil the excess tube on the far side of the road instead of next to the counter. If that doesn't help, you may need to place two counters, one on each side of the road.