The network-level approach is characterized by top-down logic, system optimization, aggregate data, large data and resource requirements, and sophisticated models. Its chief advantages are that it can:
- Optimize solutions for the entire network. By definition, this is what a network-level approach does. For instance, a network-level approach can optimize the cost-benefit ratio for the entire network. This would seem the most logical since the system, rather than an individual project, is the overarching concern. Project-level approaches attempt to replicate this ability by assigning project priorities that are commensurate with network-level programs, decisions or budgets. However, because projects are already planned before high-level decisions are made, project-level decisions and priorities may not be consistent with network-level decisions and priorities. This can lead to a suboptimal system solution that is driven by individual project-level decisions instead of network-level decisions.
- Quickly and accurately produce conditional scenarios. Software models using a network-level approach allow the user to adjust top-level budget and policy inputs and then quickly calculate the resulting network-wide effects because these models are driven by top-level (network-level) decisions. For example, a network-level model could calculate the economic and pavement conditions effects of a proposed lower axle load limit law or the long-term network performance under varying levels of funding. Conversely, project-level software is generally driven by low-level inputs and thus, a change in top-level budget or policy would be input into the system by adjusting the multitude of lower-level inputs – a more laborious process.
- Prioritize broad areas of maintenance, rehabiltation and reconstruction (MR&R). Since network-level analysis provides target MR&R treatments and costs, these targets can be easily and consistently applied to individual projects. In order to accomplish the same thing with a project-level approach, network-level targets need to be provided in advance such that project-level decision can be made with network-level targets in mind.
- Use consistent inputs in scenario comparisons. Using a network-level model, different scenarios can be modeled on the same system. This helps if each scenario is modeled using consistent assumptions models, outcomes may still be able to reflect appropriate qualitative and comparative results. Project-level approaches have more difficulty in this area because basic assumptions must be input on the lower, project level. As this is done agency-wide, communication problems and personal/geographic bias may have a substantial effect on input consistency.
- More easily obtain top management attention. At the 1997 New Orleans pavement management workshop, many pavement management practitioners raised the following issues: (1) pavement management had lost the attention of top management because they did not understand its capabilities or importance, and (2) some managers haphazardly overrode pavement management recommendations with little or no though to network implications (Zimmerman, Botelho and Clark, no date given). With its conditional scenario capability, a network-level approach could easily show the fiscal importance of pavement management as well as the implications of various decisions.