Lot’s of St Peter’s residents have contacted me concerned about car crashes, fumes and noise coming from Southern Link Road. Lots of money has been spent on this road and I’m realistic enough to know it’s not going away!

What can we do? Is there anything we can do to try and reduce the impact on local residents? There are lots of ideas being suggested – crash barriers, reducing the speed limits, introducing average speed cameras, traffic light control at the roundabouts but perhaps the simplest idea is to introduce rumble strips on the roads approaching the roundabouts.

But what about the noise they make? There are two places where there houses are quite a long way away – see purple marks on sketch here:

 

 

 

 

 

OK – so maybe houses at those points are not very close but surely noise travels?

I’ve spent some time listening to the rumble strips on the Claines roundabout on the A449. To my uncalibrated ears I’m very confident that rumble strips will not cause a noise problem to residents. But how can I prove that? This lead me to make an online request for someone with experience of noise measurements. Take a bow Alan Whitfield of A&J Acoustics for stepping forward. Alan is a retired university lecturer specialising in noise.

 

 

 

 

 

The results of our sound measurements will surprise most people. The sound inside a car on rumble strips is quite loud. Surprisingly the sound outside at just a few metres away is very different. In fact our measurements could not detect a difference in the sound energy level between road with and without rumble strips. I believe the reason for the large difference of sound levels between inside and outside the car is due to two factors. Inside you are physically connected to the metal box and additionally sound energy dissipates with an inverse square law where if you double the distance it doesn’t just half the noise but does in fact quarter the noise.

Thanks once again to Alan for giving his time so freely to help our campaign.