I like interactive maps that represent interesting, infrastructure related data (as many of the posts in this blog attest). So when I found out that the U.S. Department of Transportation released a national transportation noise map, I had to check it out – especially to see what things look like in Southeast Michigan
Clicking on the map link takes us to a map of the continental U.S.
Zooming in on Detroit we get the below image with noise levels overlaid on a street map– hmmm…. I wonder where the Airports are?
The darker colors represent higher 24-hour average noise levels and they are clearly focused on major roads/highways and on Detroit Metro, Willow Run, Detroit City and Oakland County International airports.
If we pull up the legend, we can see the reported average noise values are on the ground:
The first link in this post also has an equivalent description of these decibel ranges and a comparison chart can also be found at this link to a Yale University site
Although the noise levels are not dangerous (unless you’re standing on the runway), and are mainly below decibel intensity of a normal conversation, this map clearly shows that much of metro-Detroit regularly hears transportation noise – primarily from Airplanes.
With the introduction of noise regulations, improved technologies and other mitigating techniques, things have gotten better but the noise is still there at some level. Much of this noise comes from Detroit Metro whose primary runways are aligned in a NE – SW direction. Was that taken into account when the runways were built? With Aerial photographs from DTE we can track the evolution of this airport. I’m curious if the runways were always in these headings (North is always up in these Photos)
1949 (the original airport- construction has already begun on new the new runways)
1956 (new and old runways) – the new runways are in their present orientation
1997 (couldn’t get the southern half of the airport)
And today (courtesy of Google)
It looks like since the mid-50’s, the runways were oriented in the direction they are today, making much of the take-off/landing traffic head out over metro Detroit. Infrastructure choices have consequences and that is clearly apparent in the noise maps!