During the construction period, noise from contractor's machinery can disturb the immediate surroundings. However, noise must not exceed limits set for this phase. (photo: Bill Jacobus)

A series of work activities during the construction period will generate noise. This may include, for example, digging work and the transport of materials to and from the construction site. Railway and vehicle traffic will then create noise, once the construction is complete.

To evaluate the noise impact, we will be mapping the noise from the construction period and from the completed construction and comparing this with the noise from the current ferry operations.

Computer models used to calculate noise levels
Noise maps are created using calculations designed to create a three-dimensional computer model of the investigation area. A series of parameters that influence the noise emission in the investigation area are integrated into the computer model. This may include terrain surfaces that either absorb or reflect noise, weather conditions, reflections or noise screening caused by buildings.

When for instance noise from road traffic is calculated, traffic data from a given layout can be incorporated in the computer model. Noise from the construction period will be calculated in a similar way using noise data for work activities, such as driving with digging machines and loading and unloading of materials.

Comparisons between previous and current conditions
Noise calculations form the basis for a comparison between the existing noise profile, i.e. current ferry operations and the anticipated noise profile from the new fixed link.

These noise calculations are also used to investigate the noise impact on the environment from different layouts and traffic scenarios. These noise calculations can also be used to illustrate the effectiveness of noise-reduction initiatives, such as noise screens and barriers.