We recently blogged about a research project to evaluate a new type of rumble strip that produces significantly less external noise than traditional designs. The above video, shot near Thief River Falls, Minnesota, shows a comparison between traditional rumble strip designs and the newer, “sinusoidal” rumble strips (a.k.a. “mumble strips”).
The life-saving benefits of rumble strips are well-established, but traditional designs produce external noise that residents consider to be a nuisance. The issue has pit safety concerns against quality-of-life concerns in some parts of the state. Researchers are investigating whether sinusoidal rumble strip designs, which are much quieter, are effective enough to combat drowsy or inattentive driving.
The video is not exactly a scientific comparison, but it does give the viewer a good sense of the difference in noise levels produced by the two styles of rumble strips. The results of the actual research project are expected to be available later this year.
Crossroads 
It seems like the sinusoidal strips emit at a higher frequency. Any thoughts on whether this might reduce effectiveness for older drivers?
Had a chance to check these out. Impressed!
It will be interesting to see the Final Research Results.
The plans with details specifying the location of the Rumble Strips make a big difference in the number of vehicles driving over them and thus the irritating Noise created that nearby residents complain about.
In the tests/trials of the two types, is there a combination of the two?
Personally, I like the idea of the Centerline Rumble Strips, especially placed along curving two-lane roads where many people cross over during the winter when Snow covers the Centerline Striping.
Are there any areas near the Twin Cities where they are running a test of these two methods?
Thanks for producing this video. It will be very helpful