Tool selection is based on many variables, such as project type, size, complexity, facility type, level of detail, analysis level, data requirements, desired metrics, tool functionality, and industry standards.

Figure 4- 1

in

Chapter 4

can be used to gain a general understanding of tool selection based on level of detail, analysis level, and resource intensity. Some projects may need multi-resolution analysis, which could necessitate the selection of more than one tool for analysis. In these circumstances, refer to the Multi-Stage Analysis section of

Chapter 4

.

For further guidance on tool selection, see the following:

Calibration is the process of adjusting model parameters so that the model results accurately represent field conditions, which is necessary when developing a base conditions model using Microsimulation (Microscopic) tools such as Vissim. Typical characteristics to calibrate include traffic volumes, travel times, and queue length. It is recommended that calibration characteristics and critical calibration links (i.e., segments with weaving, bottlenecks, a volume-to-capacity (v/c) ratio > 1, etc.) be listed on the

Scoping Form

and a calibration map be attached to the

Scoping Form

. Other tools may necessitate calibration, and relevant calibration characteristics and important links to calibrate can be specified on the

Scoping Form.

See

Chapter 13

for detailed information on calibration methodology and procedures.

Performance measures objectively report project conditions concerning specific criteria. Traffic analysis performance measures are often related to mobility and may include safety, accessibility, reliability, and others (see

Chapter 5

and

Chapter 6

for Safety MOEs). Analysis tools selected for a project often determine which metrics will be used to evaluate project conditions. However, project specific circumstances may merit the selection of a certain performance measures. Performance measures are selected based on the vision, mission, goals, and objectives of the project. Common performance measures and MOEs reported by common analysis tools are shown in Table 4-4 of Chapter 4.

For further guidance on MOE applications, see the following: