M50 "rumble" patches

loyatemu

The recently resurfaced section of M50 around Leopardstown has "patches" on the road every couple of hundred metres, similar to the patches you see at traffic lights for the road sensors.

These patches are elsewhere on the M50 too, but the ones on the resurfaced section have edges that have been left higher than the rest of the road so there's a pronounced rumble when you drive over them. It's loud enough that you can hear other cars driving over them from inside your own car. Anyone who has driven on this section will know what I'm talking about.

What are these for? And why have they been left like this when they aren't above the road level elsewhere?

woejus

https://en.wikipedia.org/wiki/Induction_loop

Probably will be beat flush into the road surface over the next few years by passing traffic.

loyatemu

I wonder why they need so many of them along the M50? There multiples of these patches between each junction.

I've never come across them being installed with such high/noisy edges elsewhere on the motorway network.

yannakis

loyatemu wrote: »

I wonder why they need so many of them along the M50? There multiples of these patches between each junction.

Monitoring average speed vehicle numbers.

mollser

I live very close to the M50. The resurfacing works were said to reduce noise levels. Which it has in the main. However these rumble strips make an incredibly loud noise which is really noticable at night time. And if you stand by the tennis courts in Westwood the echo of the sound protection barriers is actually unbelievable. Can't believe their work was so shoddy on these - the surface otherwise is immaculate.