Preliminary Alternatives Report

Preliminary Design Study and Environmental Assessment
Highway 417 (Ottawa Queensway), from Highway 416 to Anderson Road
G.W.P. 663-93-00 C.A. 4005-A-000090

March 2004

Volume 1

Table of Contents

List of Figures

Figure 1 - Study Area Map
Figure 2 - Evaluation Flow Chart
Figure 3 - Sample Weighting of Factor Areas

List of Tables

Table 1 - Long List of Factors and Sub-Factors
Table 2 - Sample Weighting of Sub-Factors for Natural Environment Factor
Table 3 - Summary of Assessment and Evaluation of "Alternatives to" the Undertaking
Table 4 - Long List of Interchange Alternatives
Table 5 - Preliminary List of Applicable Factors / Sub-Factors for Each Alternative Group

Appendices*

Appendix A - Function Forms

Appendix B - Calculation of Weighted Score

* Note: These appendixes are not available online.

Volume 2: Alternative Plans

List of Plates

Glossary of Terms

Accessibility:

Ease with which people can reach their destinations. Ability to reach a desired destination at a reasonable cost with reasonable choices.

Alternative:

Well-defined and distinct course of action that fulfills a given set of requirements. The EA Act distinguishes between alternatives to the undertaking and alternative methods of carrying out the undertaking.

Congestion:

When the demand for travel on a portion of the transportation system is greater than the ability of that portion to handle travel efficiently.

Dichotomous Utility Function:

A utility function that represents a desirable or undesirable response (yes/no, present/absent, true/false).

Double Counting:

Unintentionally accounting for a particular condition more than once through the selection of a number of sub-factors and measures during the evaluation method.

EA:

Environmental Assessment

Dimensionless Number:

A number that does not have a measurement unit, such as length, associated with it. Examples include utility score and overall score.

Evaluation Process:

The process involving the identification of those factors, sub-factors and measures that help to distinguish between the alternatives under consideration, rating of predicted impacts, assignment of weights, and aggregation of weights to produce an ordering of alternatives.

Factor:

A component used to identify a particular consideration within each factor area. For example, under Natural Environment, factors could include wildlife, fisheries, vegetation and groundwater.

Factor Area:

A broad component of the environment such as Natural, Social, Economic, Cultural, used to group factors used during the assessment and evaluation of alternatives.

Function Form:

See Utility Function.

Linear Utility Function:

A function that can be defined using a linear equation of the form:
y = a + bx, where
y is the dependent variable (raw score);
x is the independent variable (measurement);
b is the slope of the function; and
a is the y intercept, normalized in this study to be equal to one or zero.

MTAC:

Municipal Technical Advisory Committee

Mitigation:

Taking actions that avoid, prevent, remove or alleviate to some degree the negative impacts associated with the implementation of alternatives.

Mobility:

Ability to satisfy the demand to move a person or goods. Reaching a desired destination with relative ease within a reasonable time.

Overall Score:

The final value of an alternative's score derived at by summing all of the weighted scores.

PAC:

Public Advisory Committee

Performance Factor:

See Utility Function.

PIC:

Public Involvement Centre

Ranking:

The ordering of alternatives from first to last for comparison purposes.

Raw data:

The measurement of the impact, or measured data, under each measure/sub-factor.

Risk:

Probability that a given outcome will or will not materialize. Distinct from uncertainty in that the alternative outcomes are known or defined and that the probability of each is measurable.

Screening:

Process of eliminating alternatives from further consideration. Alternatives may be "screened out" if they do not address the identified problem/opportunity, if they do not meet specified conditions or requirements and/or if they would result in unacceptable impacts.

Step Function:

A function can be defined by several linear functions within separate ranges that have a slope equal to zero. For this study, two linear functions are used:
y = 1, for x = desirable
y = 0, for x = undesirable

Sub-factor:

Explicit feature or consideration used for comparison of alternatives. Each subfactor is grouped under one of the factors.

TAC:

MTO / TSH Technical Advisory Committee

TTC:

City of Ottawa Transportation and Transit Committee

Traceability:

Characteristics of an evaluation process that enables its development and implementation to be followed with ease by someone reviewing the work.

Utility Function:

A function (linear, step) that represents the utility score versus the sub-factor's measurement or desirableness.

Utility Score:

The "y" value derived from the utility function of the measurement of the impact induced by a particular alternative's sub-factor/measure (a number between 0 and 1).

Weight:

The importance attributed to a factor area, factor or sub-factor relative to others. The value of the weight is expressed in a percentage and the sum of all weights is equal to 100%. A range of weights is used to test the sensitivity of the result to the range of community values.

Weighted Additive Method:

The arithmetic method used in the evaluation of alternatives, which reduces the relevant measures into a dimensionless number for each alternative, suitable for comparison.

Weighted Score:

A raw score that has been multiplied by the factor weight.

Contents | Introduction | Problems & Opportunities | Assessment Methodology
Alternatives to the Undertaking | Alternative Methods