When sectional rehabilitation suggestions have been carried out for the whole road network or for any group of sections, it is possible to generate a complete maintenance plan using optimization algorithms with the goal of minimizing the total costs under the given yearly budget restraints.
It may also be chosen to base the plan on the cheapest solution for the agency or the minimum total costs without considering the yearly budget levels.
Further, it is possible to only respect the budget for a specific number of years.

Different options are available for the selection of method of budget based optimizations:
The “Decremental” and “Incremental” methods starts respectively with the solution with minimum total costs and the solution with minimum agency costs and make use of an algorithm based on Toyoda’s "effective gradient" to search for the solution that will give the minimum overall costs, while respecting the budgets.

The “Genetic” method makes use of a genetic algorithm to find improvements to any existing solution.
The “Fit Budget” option is based on the genetic algorithm, but pursue the combined goal of minimizing the total costs and minimizing the difference between yearly budget and yearly costs over the optimization period.

The detailed results can be viewed in terms of sectional maintenance lists, and the overall network results can be saved for later study, and comparisons with optimizations carried out under different assumptions.

In figure 10 is shown a graphical comparison between 2 optimizations, with the effects on the overall predicted performance of the road network.

Figure 10: Comparisons of road network level performance.

The green curves reflect the solution with the cheapest agency costs, while the blue curves gives the results of an optimization with the goal of achieving the most cost-effective solution under a given budget.

The effects on the “Total” graph in the lower right corner are obvious, with a significant reduction in total cost for the additional invested agency costs.

It is also seen that in the first couple of years, expenses can not be kept under the budget level, which is a typical sign of a road network, where rehabilitation activities have been constantly pushed forward for short term money saving purposes.

For all four performance graphs the terminal condition of the road network is improved, compared to the cheapest solution.