The decision tree for pavement treatment defines the rules that indicate need for pavement treatment. The tree contains both the need for treatment and the type of treatment required.
In AgileAssets software, a full decision tree is the combination of an upper-level decision tree (built in the Upper Level Decision Tree window) and a lower-level decision tree. Lower-level decision trees are created and attached as an extension of the upper-level decision tree in the Decision Trees window.
Lower-level decision trees are grouped in sets. The software supports an unlimited number of decision tree sets, which gives you great flexibility in creating various decision trees for use in optimization analysis. Each decision tree set is categorized as either a General decision tree set or an INCBEN decision tree set. The differences between General and INCBEN decision tree sets are described below:
- General Decision Tree Sets: For a General decision tree set, several lower-level decision trees can be assigned to the upper-level portion of the decision tree. The lower-level decision trees can have only one treatment assigned per limb. During analysis, then, a road section can have a treatment recommended for each lower-level decision tree that is bundled together. The final single recommended treatment is the one with the highest treatment priority (see the Treatments window).
- INCBEN Decision Tree Sets: For an INCBEN decision tree set, only one lower-level decision tree can be assigned to the upper-level portion of the decision tree. The lower-level decision trees can have up to three treatments assigned per limb. During analysis, then, a road section can have several recommended treatments. The final single recommended treatment is determined internal to the INCBEN algorithm, which uses a sliding scale where:
- The treatment with the highest benefit/cost ratio is chosen when budgets are lean; and
- The treatment with the highest benefit is chosen when budgets are ample.