Slow traffic to ascertain need for sound barrier

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By Patricia Max

There has been a great deal of discussion regarding MIG’s proposed roundabout design for NM 502/Trinity Drive. However, another project related to NM 502 that MIG has also been involved in has received very little coverage.
Residents of the Eastern Area have drawn the county’s attention to the increased traffic noise in their neighborhood by asking for the construction of a sound barrier – a wall – to muffle the traffic noise.  
Rather than determining if the decibel level is such that federal regulations would require mitigation, and if that mitigation should be the construction of an 8-foot tall, 1,000-foot long wall, the county council directed MIG to propose a design for a sound wall as the Eastern Area residents requested in their petition.
There is no doubt that there is increased traffic noise along the section of NM 502 between Airport Road and Tewa Loop. The following three factors have contributed to this increase:
•The change in speed limit in the late 1990s on that section of road. Going west the speed limit changes from 50 mph to 40 mph between Airport Road and Tewa Loop and from 40 mph to 35 mph across from East Park Pool.  Prior to this change, the speed limit changed from 50 mph to 35 mph at Airport Road.   
Going east the speed limit changes from 35 mph to 40 mph between the two driveways into East Park Pool and from 40 mph to 50 mph between Tewa Loop and Airport Road.  Prior to this change, the speed limit changed from 35 mph to 50 mph just east of Airport Road.
Faster moving traffic makes more noise.
•A large increase in county and Los Alamos Public Schools traffic, traveling at the higher rate of speed from Airport Basin to the townsite and back again. This traffic includes buses, large trucks, pickup trucks, different sized trucks pulling different sized trailers loaded with various types of equipment, and probably midsize cars. As far as I know, as part of the Airport Basin construction the county neglected to evaluate the effects of that traffic on the Eastern Area residents.
•A large number of trucks with destinations in the townsite at various construction projects, such as the Justice Center, Los Alamos High School and Diamond Drive. Other large trucks also contribute to excess noise because there is no longer a sign east of the Y directing all trucks to use the truck route between 7-9 a.m. There is an indication that some truck drivers are confused by the current sign, which directs all trucks to the Los Alamos National Laboratory inspection station on the truck route so the signage has effectively diverted all truck traffic to the Main Hill Road.
The higher speed limits affect the noise 7 X 24. Therefore the first effort to mitigate the noise should be to slow down the traffic and enforce the lower speed limits.
Those residents whose homes are closest to NM 502 are impacted more than those who live farther north of NM 502 and should quickly be able to determine if there’s a change in the noise levels.
Because of the problems that surfaced with MIG’s roundabout design, relying on them to do a thorough noise study, to examine the federal regulations for noise abatement, and to propose a solution, not just rubberstamp a wall, is problematic.
Although the residents of the Eastern Area are negatively affected by the noise caused by the higher speed limit, the increased county and schools traffic, and the impact of increased truck traffic — all Los Alamos residents will be affected by changes to the entrance to Los Alamos — so any solution must include evaluating the comments of all Los Alamos residents, not just the residents of the Eastern Area.

Patricia Max
Los Alamos