Instruction manual

Appendix E.5 One vehicle Shown as Two

This error is normally caused by a vehicle with an axle spacing greater than the maximum axle spacing setting in the

configure system option. The counter defaults to 40.0ft. This value can be changed in the unit by the user if needed.

If you increase this value, you run the risk of counting vehicles traveling close together as one vehicle (two tailgating

cars become one vehicle, usually turned into a four axle Class #8 under Scheme-F). However, the default axle

classification table does have a definition to look for such instances and move them to a class 2 instead to correct this

issue. A car closely following a truck will generally turn that truck into a class 13 under normal operation. To alleviate

this from occurring, the Phoenix II has a tailgating feature that is specifically designed to look for tailgating vehicles.

Note: This error can also be caused by missed axles. The Phoenix II only resets its’ time-out value after each axle hit, if

you miss some and the counter does not reset its value, then the vehicle will be ended prematurely.

Appendix E.6 Two Vehicles Shown as One

This error is normally caused by two vehicles tailgating in the same lane at lower speeds. The default maximum axle

spacings are 40.0ft in the Phoenix II but can be changed by the user. Decreasing this value may alleviate tailgating but

will break apart class 9 trucks as they have large axle spacing between the tractor and trailer axles. In city traffic this

can also be a more common occurrence as traffic is traveling slower and will be more inclined to be traveling closer. To

alleviate tailgating errors, a tailgating cars feature is available to look for tailgating vehicles.

Another scenario in which this error may occur is when two vehicles are crossing two road tubes when road tubes are

setup to classify two lanes in opposite directional traffic. This error is more common in higher ADT areas and this setup

should be avoided in locations that have more than 4500 ADT (average daily traffic). We also recommend decreasing

the road tube spacing to 4ft to minimize the occurrence of errors.

Appendix E.7 Road Tube Setups That Do Not Cause Errors

The following section describes road tube issues which do not cause errors. This is included to dispel any suspicion

about these issues causing problems.

Coiled Road Tubes.

The effect of coiled road tubes versus non-coiled road tubes does not have a noticeable effect.