Thursday, June 19, 2008

Traffic noise #2 - Grogans Mill North side

Measurements were taken on June 18th using the same methods as the first in Indian Springs. This measurement is intended to see what noise is generated from The Woodlands Parkway and what surrounding noise it may create in the area of a flyover. This is a rather complex site, not typical of The Woodlands. The flyover is the one going over Grogan's Mill Rd.

North Side On Grogan's Mill Rd near the East side apartments, the traffic is fairly tame moving in a 35MPH zone, and consisting of mostly sedans emitting an average of 75db as they pass the measuring meter. In the background, one hears a low drone of less than 70db from the parkway. There is an occasional sports car or truck which will momentarily raise the level as high as 90db, but most trucks emit noise less than 85db. Even a rattling pickup truck which I expected to be notable was measured at only 78db.

On the ramp onto Woodland's Parkway, as traffic accelerates away from Grogan's Mill towards the west, the sound level is not surprisingly higher. Surrounding traffic brings the meter to 75 db regularly but not continuously. The average observed level, mostly consisting of sedans, was about 78db. Some 6% of the traffic exceeded 80db; approximately 1% exceeded 85db. There is significantly more truck traffic coming under the parkway than from the north, and turning on to the ramp; this causes higher levels of noise at this location. I observed about a 3db increase in the average level of sedans and trucks at this location in short 10-15 second spurts as the traffic light at Grogan's Mill opened two lanes of traffic to turn on to the ramp. Typical measurements were: Concrete truck- 80, tow truck - 82, SUV with loud pipes - 87 db, sedan with loud pipes - 85 db, pickup truck with loud pipes - 90+ db. Pickup truck with loud bass audio speaker - 90db. A nearby HEB 18-wheeler transport truck registered 80 db even though it was far away and not directly passing by. A typical traffic burst would have about 12 seconds duration emitting noise at a 82-83 db volume, usually produced by two concurrently occupied lanes of traffic.

Then next measuring location was on the parkway itself on the northern side, as the traffic began to descend down the flyover. There were of course more trucks on the freeway than Grogan's Mill. The 45+ MPH speed of the traffic certainly cranked up the volume. A typical sedan emitted a 81 db level of noise. Traffic moved in bursts, controlled by the traffic light at Six Pines. Each here also burst and would last for varying times, from 20 seconds to 45 seconds. Each burst would typically range from 83-88 db 10-12 feet from the source. Here one could discern differences in tires, much more so than at lower speeds. A higher frequency pitch would be emitted by some tires. Some pickup trucks or vans with loud mufflers would ratchet up the volume into the 90's. There were several trucks that exceeded 90db and one dirt dumpster was measured at 99db. I asked myself where all of this noise was going, because below the flyover, I could hear very little of it. I concluded that the sound waves probably go up more than down because the road itself reflects the sound, and a lot of the irritating noise comes from mufflers, not the road.

South Side Measurements
I will be measuring the other side of this flyover in a few days and simply adding it here.

Tuesday, June 17, 2008

Traffic Noise in The Woodlands Texas - Indian Springs

I have been concerned about the growing road noise level in Indian Springs for several years. This article documents my first findings after recently measuring the noise but does not provide any commentary on the results. I am holding that pending more investigations, additional thought and others' opinions. There has not been much data that I could find to indicate whether the noise here is normal or abnormal, except in the Handbook of Road Technology reference below. I decided to take a pragmatic view of the issue and measure the noise level we experience here at peak traffic times - at rush hour in the morning and in the evening to compare with observations elsewhere.
Traffic noise consists of a varied number of components which affect our comfort level in different ways. Variables which affect the volume and frequencies of the noise include road surface, tire material and style, fuel of the automobile, muffler, transmission gear ratios, weight of the automobile, stereos and speakers, velocity of the automobile and the performance of the driver. Higher frequency noise is rapidly reduced by vegetation and distance, whereas low frequencies are not so easily attenuated, travel further distances and tend to bother residents more.

Typical sound volume benchmarks are easily related to traffic noise volume.

  • Each 10 db increment doubles the volume, therefore 100 db is 16 times 60db
  • If it sounds loud, it measures loud
  • If you hear it in the house, it is dominated by low frequencies
  • Public annoyance legal threshold is 85db
  • Sustained exposure may result in hearing loss at or over 95db
  • Short term health danger begins at 105db
  • Maximum measurable noise level is 194db
  • Piano Fortissimo is 84 to 103db
  • Acceptable perceived levels are dependent on time of day or the individual's daily routine - some people work at night
  • Acceptable perceived levels are dependent on type of neighborhood and expectations in the living style of that neighborhood
  • OSHA declared a time criteria for exposure to various sound volumes
    • Maximum daily 8 hours at 90db
    • Maximum 1.0 hour at 105 db
  • If it hurts, it is usually over the legal limit in any public place
  • If house visitors ask about it, it is generally too loud
Measured benchmark reference data
  • TV at normal listening volume = 56db
  • TV at full volume = 78 db
  • Birds singing = 63 db
  • TVfull = 5 times volume of Tvnormal
  • Birds singing = 1.6 times Tvnormal
Method of measurement
  • Near source measurements 8+ feet away
  • Radio Shack Sound Level Meter mounted on tripod
  • No frequency measurements were taken
  • Visually measured instant peak volume only
  • 35 MPH speed zone
  • Three and four lane road at three nearby locations
  • Measured on concrete and asphalt surfaces
  • Equipment sensitive to wind velocity n- did not measure in high wind
  • Measurements taken at peak morning and afternoon traffic situations
  • Observations relative to the benchmarks and information above:
  • Typical sedan = TV at full volume
  • Loaded concrete truck = 1.8x sedan
  • Diesel pickup = 3x sedan
  • Pickup with loud mufflers = 5x sedan
  • 18-wheeler = 5x to 16x sedan
  • Most motorcycles = less than sedan
  • Motorcycle with loud pipes = 12x sedan
Observations in db
  • Concrete truck - 88db
  • Loud sedan - 90db
  • Most sedans - 77db
  • Heavy duty truck - 81db
  • Accelerating Sports car - 86db
  • Motorcycle with loud pipes - 90db
  • 18 wheeler moving van - 92db
  • Diesel pickup truck with loud pipes - 94db
  • Van with loud pipes - 92 db
  • Loudest vehicle observed - 97db
My estimate is that about 3% of the automobiles passing by at this location were registering above 85db at my measuring station.
  1. Galen Carol Audio
  2. Handbook of Road Technology

Sunday, June 15, 2008

Woodlands Texas Alert System - emergency and residential information now including Woodlands Watch being distributed

Over the past few years, as the community has grown, so have the issues for distributing timely and pertinent information to residents. The Woodlands Association service company is now providing and supporting a new information system for this purpose. The first Woodlands Watch message was distributed this past week revealing a start up glitch which was quickly corrected and redistributed to those residents who had signed up for the service. This particular message told residents about a robbery at a home in one of the villages. It gave pertinent information for resident awareness and advice on how to deal with the situation. This new system will be very helpful to residents who want to feel that they know what is going on about them and also for anyone physically close to the actual event, so that they can take appropriate measures for their own safety. It is my opinion that this information should not be distributed outside this community by subscribers unless there is a specific requirement to do so. That could be a legal issue which might violate the privacy rights of others.

There is another issue that residents ought to know about. A legal inquiry has been issued whether the data on the server falls into public domain as prescribed by the open information act. If it is ruled open information, the email addresses would not be private. They would be available to anyone requesting the addresses. If you have a Yahoo email address, you may have an alternative email address available for phishing, and I would suggest using one of them. Mail to a phishing address is forwarded to your email address and treated by Yahoo as if it was email directed at your normal email address. There may be similar services by other internet providers. Check into your service provider for advice on how to handle such situations.

I do recommend that you subscribe to this service! A picture-gram on how to use it:

Related Article: Announcing the new communication service of The Woodlands

The system is easy to use. More than one member of the occupant of a home may register and acquire different information. You must be a resident to receive the distributed information. Go to The Woodlands Association web site to sign up and select your preferred options.

Make sure you save your changes after you have selected what you need. Then log out.

Monday, June 2, 2008

Montgomery County Sheriff Citizens Academy

For those of you who would like to understand law enforcement a little bit better or even a whole lot better, Montgomery county has an excellent program to not only inform but also encourages you to participate and support this county's law enforcement agency. It is the citizen's academy. You can find current information on the Sheriff's web page. The next class is being conducted in August '08. There is a maximum enrollment of 30 students, so you if you want to learn, get on the stick!

Here is what you get for your $35 and 42 hours of class instruction:
+ How the Sheriff Department operates: recruiting, jail, crime stoppers, DWI enforcement, firearms, auto theft, communications, internal affairs, use of force, S.W.A.T., patrols, narcotics and vice, CSI, homicides, computer crime, victim advocacy, finger printing, lie detectors
+ Lots of laughs
+ Some very serious moments
+ Jail tour
+ Hands-on sobriety testing, lie detector, issuing a traffic ticket, armaments
+ Ride-along with patrolman, full shift
+ Membership in Alumni association - participation in their events.
+ Nice shirt
+ Photo of class
+ New friends
+ Graduation certificate