Determine the peak hour percentages in terms of the percentage of total daily traffic that is occurring in the AM/PM peak hour for both the peak hours. The percentages are intended to be a representation of the existing traffic patterns. Typically, traffic counts are collected in the form of TMCs and/or tube/camera counts. Assuming traffic counts are taken on a typical weekday with no major events or disruptions, they represent peak hour percentages for the AM and PM K factors. The peak hour percentages are then applied to the ADT to develop projected AM and PM peak hour volumes. Validate the traffic counts collected against STARS data, previous counts, or traffic forecasts. Please note that AM and PM peak hours are not always inversely related.

Turning movement traffic projections are estimated by applying existing turning movement count percentages at each approach to the ADT volumes. The TMCs are typically rounded to 50-vehicle increments, to avoid an overestimation of traffic on side streets. Traffic projections are then balanced along the corridor.

A corridor planning project involves evaluating and comparing different alternatives to determine how closely they meet the study goals and objectives.

Table 7-1

lists objectives for a typical corridor planning project. The performance measures quantify how objectives perform when compared to existing or future conditions. Note that the table does not include all objectives, performance measures, sources of data, or tools for analyzing a corridor planning project.

Table 7-1

is provided as a first step and guide for establishing basic objectives and how to measure them. The table provides sources of data as well as tools that can be used to evaluate the performance measures. Scoring metrics are generally developed to rank the different performance measures based on stakeholder feedback, public involvement, and the goals and objectives of the study.

In addition to the performance measures listed in

Table 7-1

, other evaluation criteria could be considered, such as ROW availability, environmental impacts, and public input.

1

The tools presented here are general tools used for various levels of analysis. Depending on the level of analysis, different tools could be needed. Individual analysis chapters have more information regarding the type of tool to use for different levels of analysis.

Existing conditions analysis is a key step in evaluating a corridor. An existing conditions analysis provides a baseline condition to compare future improvements. It also helps determine if the overall improvements being recommended provide a benefit and meet the study goals. The existing conditions analysis includes various types of analysis, depending on the type of corridor planning project. The analysis level for corridor studies is typically planning-stage and the types of tools to be used for the analysis are typically sketch-level or macroscopic tools. This may include tools such as CAP-X, GIS, or TDM outputs, depending on the extents of the analysis and scope of work. Ultimately, the type of tool and analysis is determined based on the objectives and the corresponding MOEs that quantify the corridor study goals. These objectives and MOEs may be selected from

Table 7-1

above. The same analysis tools and MOEs are typically used for evaluating both existing and future conditions. The chapters from this document listed below provide more detail on the types of analysis that may be performed to evaluate existing conditions

A future conditions analysis is developed using the traffic projections and analyzing future nobuild and build conditions using the projected traffic volumes. Traffic analysis of future conditions is typically based on opening year and/or design year. Typically, traffic volumes for future no-build and build conditions analysis remain the same. However, there could be some exceptions for new alignment routes, access modifications, and existing facilities with oversaturated conditions. Discuss and document any exceptions.

The

No-build analysis

is developed using the existing conditions plus any committed projects that could be built between the existing year and future analysis year. This analysis determines the impact of future traffic growth on MOEs if existing conditions and committed projects remain in the future. It also provides a comparison between the current conditions (existing conditions analysis) and traffic conditions in the future if no further action is taken.

The

Build conditions analysis

is developed by analyzing improvements based on issues observed in the existing conditions and future no-build conditions. Build conditions analysis includes alternatives analysis, which is a decision-making process where multiple alternatives are evaluated to select a preferred alternative. When evaluating future conditions, it is important to have several mitigation options, as some could be more favorable than others, based on stakeholder input, ROW impacts, the B/C ratio, or environmental factors. To evaluate multiple alternatives, develop a screening process and an evaluation matrix based on MOEs, stakeholder inputs, and other constraints. See

Chapter 8

for more information on developing alternatives, screening process, and evaluating alternatives.

There may be instances where a corridor does not have congestion-related issues, but safety is an issue due to roadway geometry, incomplete traffic control, faulty pavement markings, low quality signage, or other reasons. Rural segments of corridors are often more inclined to have safety-related issues than congestion-related issues.

Similar to traffic analysis, safety analysis is performed for two conditions, existing and future. The purpose of safety analysis for existing conditions is to identify existing safety issues and develop safety countermeasures for those issues. Existing conditions safety analysis methods include:

The purpose of the future safety conditions analysis is to consider safety implications of alternatives that have been developed. Future conditions analysis can be conducted in a variety of methods, some of which are listed below.

More information regarding how to perform existing and future safety analysis is presented in

Chapter 5

and

Chapter 6

.