Visual Impact Assessment

Understandably, most activities during the construction phase itself will have a visual impact on the area, given the presence of the worksite. But the impact level on the various groups (residents, transport network users, visitors, etc.) will vary.

The main group to feel the visual impact of construction will be hotel guests and people living in residential areas near the interchange, along with tourists and visitors. The extended presence of worksites in the visual field of residents and users will lead to deterioration in the landscape quality. This factor must not be overlooked.

The impacts deserve even greater consideration seeing that Montréal-Trudeau is a major gateway to the city. The construction period will thus cause deterioration in the quality of urban life, a reduction in landscape integrity and for visitors difficulty in finding their way around. The level of the impact here is assessed as being average.

Certain attenuation measures can be applied during the construction phase to reduce the impacts on the landscape in the study area. They include:

x Replace destroyed vegetation and provide protection for mature trees before the work begins.

x For each situation, ensure careful arrangement of worksites and deposits of materials to limit direct views of the work zones.

x Close up the worksites to prevent views of the entrance-ways on the part of heavy vehicles and equipment.

Despite the application of these attenuation measures, there will still be an impact to some extent on the visual environment during the construction phase.

Operational Phase

The assessment of the project’s visual impact after completion is broken down into three main categories, one for each component of the overall transport infrastructure. These categories are:

x the highway network and the major access route to the airport, which serves as the gateway to Greater Montréal;

x the rail network, which has its own operational parameters and clientele;

x the local road network, which is used mainly by residents and workers in the district, and includes public transport.

IMPROVING THE LAND TRANSPORT INFRASTRUCTURES IN THE EXECUTIVE SUMMARY VICINITY OF MONTRÉAL-TRUDEAU AIRPORT

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Current

The impacts during the operational phase, i.e., after construction is completed, will be felt by users who live or work closest to the structures that will be built under the project.

Impacts will also be felt by the creation of the major axis made up of the rail link and airport/highway links that run through several landscape units. These new rail and highway infrastructures will modify the field of vision for each landscape unit to varying degrees.

The project will affect a wide range of user groups, each with its own behaviours, expectations and perceptions. Therefore, the visual impacts have been broken down per infrastructure type in order to identify effective and appropriate corrective measures for each intervention under the project. The main impacts on the landscape have to do with the quality of visual corridors, the loss of a vegetation screen, visual disturbances, and the loss of coherence in the spatial organization of the road network. The majority of visual impacts have been assessed as being average.

Following are the attenuation measures proposed to counter the visual impacts on the landscape:

x Carry out specific actions (trees/vegetation, road fixtures, fringes and sidewalks, lighting) for each component of the transport network to visually reinforce the separation of the regional and local rail/road routes;

x Ensure coherence in the landscaping of this particularly congested and complex sector, in addition to the individual measures for each point of impact;

x Develop a feasible strategy for planting vegetation in the road network, i.e., one that ensures the best possible vegetation growth in such conditions.

These recommendations will serve as the basis for landscape design criteria prior to the development of plans and specifications. Specific attenuation measures are recommended for each point of impact. Following are illustrations of four situations and their appropriate attenuation measures.

1. Visual screen/Buffer zone

Here the creation of a buffer zone will provide an acceptable foreground to offset the effects of visual proximity.

Proposed

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2. Visual screen/Enhanced topography

A treed slope will ensure visual closure with an immediate effect. Doing so also limits the impact during all seasons of the year.

3. Provide roads with urban features (vegetation, urban fixtures)

Transforming a road into an urban thoroughfare is a visual integration measure that makes it acceptable to users in a highly urbanized setting.

4. Massive replanting along roads and at earthfill sites

This measure seeks to establish within a reasonable time a density of plant life that nuances the visual perception in highly urbanized settings. The planting of trees to create a wooded environment will help reach this objective.

Proposed

Proposed Proposed

Current Current

IMPROVING THE LAND TRANSPORT INFRASTRUCTURES IN THE EXECUTIVE SUMMARY VICINITY OF MONTRÉAL-TRUDEAU AIRPORT

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The impacts of these measures would be as follows:

x 8 situations constituting benefits for the area;

x 4 situations with insignificant impacts;

x 4 situations with low impacts (2 permanent, 2 temporary);

x 3 situations with average impacts (2 permanent, 1 temporary).

The two situations presenting average residual impacts are:

x the overhead crossing of the rail corridor, which presents no opportunity for attenuation;

x the extensive reorganization of the road network in the industrial zone, which would lead to a loss of visual coherence in terms of spatial organization.