As part of the operation of the Samuel De Champlain Bridge Corridor and its access routes, significant efforts have been made to improve the sound environment for residents of adjacent areas. In winter 2023, noise barrier improvements were carried out on Highway 15 South. The purpose of this document is to inform you of the results, findings and next steps.

1. MESSAGE TO RESIDENTS
Le Sud-Ouest Sector | June 2025
Sound Performance
RESULTS Samuel De Champlain Bridge | Signature on the Saint Lawrence Group
As part of the operation of the Samuel De Champlain Bridge Corridor and its access routes, significant efforts have been
made to improve the sound environment for residents of adjacent areas. In winter 2023, noise barrier improvements were
carried out on Highway 15 South.
The purpose of this document is to inform you of the results, findings and next steps.
Work Done December 2023
▶ Increasing the height of noise barriers in the Verdun sector according to an optimized acoustic model.
▶ Replacement of old opaque reflective panels with more efficient and more absorbent panels.
▶ The configuration of the opaque and transparent panels was left as is to meet urban integration guidelines specified in
the contract.
Results Achieved 2024 performance measurement
The results of the digital model* are shown in the following table:
▶ Compliance with performance criteria at the posted speed (70 km/h) at the majority of receptors, with a noise
reduction of 1 to 5 dBA depending on location compared with the sound environment prior to the project.
▶ Some deviations at the actual speed (93 km/h) that may be perceptible.
*Fore more information on how the digital model works, see the full presentation below.
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2. Results
Sector Receptor 2012
dBA 24h
Criterion
dBA 24h
2024
at 70 km/h
dBA 24h
Deviation
at 70 km/h
dBA 24h
2024
at actual
speed**
dBA 24h
Deviation
at actual
speed**
dBA 24h
D’Argenson/
Mullins
M1 55 56 56.8 +0.8 58.9 +2.9
Thomas-Keefer/
Atwater
M-A1 57 58 56.0 -2.0 57.8 -0.2
Parc d’Argenson M-A2 61 60 56.8 -3.2 59.0 -1.0
Centre /
D’Argenson
M-A3 57 58 56.7 -1.3 59.0 +1.0
Butler/
Wellington
M2 61 60 58.6 -1.4 60.7 +0.7
Knox M-B1 57 58 53.7 -4.3 55.3 -2.7
Butler/
Coleraine
M-B2 58 59 56.7 -2.3 58.3 -0.7
** Actual speed: northbound at 93 km/h – southbound at 69 km/h.
▶ The sound environment at receptor M1 exceeds the performance criterion.
▶ The sound environment at receptors M-A3 and M2 exceeds the performance criterion at the
actual speed, although the calculated deviation is below the threshold of human hearing.
▶ The sound environment at the other receptors meets performance criteria.
MESSAGE TO RESIDENTS
Le Sud-Ouest Sector | June 2025
LEGEND
Receptor
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3. Additional Factors With an Impact on Noise
The sound environment is also influenced by elements external to or independent of the Samuel De Champlain Bridge
Corridor:
▶ Actual speed substantially greater than the posted limit (+23 km/h above the limit on average on Highway 15 North).
▶ Noisy behaviour: modified exhausts, motorcycles, engine braking, road racing.
▶ Cumulative noise from neighbouring streets and areas not administered by the bridge.
These occasional nuisances can be disruptive without necessarily being reflected in daily averages.
STEPS BEING TAKEN
▶ Working with the Sûreté du Québec to enhance enforcement of the Highway Safety Code..
▶ Installation of awareness panels such as one that reads: “Réduisez le Brrrruit!”
▶ The ministère des Transports et de la Mobilité durable (MTMD)*** has been approached several times since the bridge
opened in 2019, to add photo radars.
***Currently, the MTMD considers only the accident-prone nature of a road to be a factor in determining whether a speed camera should be installed.
Next Steps
MESSAGE TO RESIDENTS
Le Sud-Ouest Sector | June 2025
Installation of new noise
barriers in the
D’Argenson/Atwater sector.
Monitoring of the sound
environment following
the installation of the
new barriers.
Comprehensive
monitoring study.
Communication with
the borough and
residents.
SUMMER 2025 FALL 2025 2026
2026 2029
Final action plan, with
work planned for 2026.
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4. Understanding Sound Levels and Auditory Perception
140 dBA
130 dBA
120 dBA
110 dBA
100 dBA
90 dBA
80 dBA
70 dBA
60 dBA
50 dBA
40 dBA
30 dBA
20 dBA
10 dBA
0 dBA
30 dBA
Quiet places
(bedroom,
daycare nap
room)
40-60 dBA
Conversation,
storytelling to
a child
65 dBA
Busy
street,
class-
room
70-80 dBA
Noisy street,
pub, vacuum
cleaner, TV,
daycare, noisy
classroom
90 dBA
Playground,
hair dryer
100 dBA
Jackhammer,
music player
at max volume
120-130 dBA
Pain threshold
for humans
Formula 1 circuit,
jet takeoff at
100 m
85dBA
Danger
threshold
for hearing
Lawnmower,
busy street
DECIBEL
SCALE AS
PERCEIVED
BY THE EAR
Source: ARS Normandie - https://www.normandie.ars.sante.fr/index.php/prevention-des-risques-auditifs-lies-au-bruit
INCREASE IN
SOUND LEVEL
MULTIPLIED
SOUND ENERGY
AUDITORY PERCEPTION CHANGE
3 dBA 2
Slight
We can tell the difference between two places if the level differs by 3 dBA, but only if we’re
paying close attention.
5 dBA 3
Clear
We notice a worsening or improvement when noise increases or decreases by 5 dBA.
10 dBA 10 Like the sound is twice as loud.
20 dBA 100
Like the sound is four times as loud.
A 20 dBA change can wake someone up or distract them.
50 dBA 100,000
Like the sound is 30 times louder.
A 50 dBA variation can be overwhelming.
Source: https://www.bruitparif.fr/perception/
MESSAGE TO RESIDENTS
Le Sud-Ouest Sector | June 2025
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