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
Preliminary Alternatives Report
March 2004
Volume 1
Table of Contents
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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
