Multi-stage analysis is a combination of analysis stages, often applied in sequence. As with alternatives analysis, study limits are well-defined and narrowed to permit increased detail. For example, if a project used CAP-X (a Planning-stage analysis tool) to determine intersection configurations and then modeled in Vissim (a design stage analysis tool) to determine the preferred intersection configuration, that would be considered a multi-stage analysis.

Multi-Resolution Modeling (MRM) involves tools with different traffic analysis resolutions (Sketch-level or macroscopic, HCM-based (mesoscopic), and microsimulation (microscopic)). It could include assessing a sketch-level or macroscopic trip table to determine overall trip patterns. It could also include using HCM-based (mesoscopic) analysis to understand impact of mitigation strategies on groups of vehicles at a lane-by-lane level or packets of vehicles in large networks. Lastly, a multi-stage analysis could potentially include microsimulation (microscopic) analysis of individual driver behavior and the impacts of traffic control strategies.

Figure 4-2

shows the MRM framework.

Partial multi-resolution models, involving macroscopic and microscopic models for networks experiencing medium to low levels of congestion, may not be able to model largescale traffic demand reroutes. This could result in macroscopic/TDM output results that may not properly represent the congestion for the various alternatives and could require further analysis using engineering judgement or different analysis techniques.