Wednesday, July 23, 2008

Montgomery County - using cameras for traffic law enforcement

What is the public opinion of enforcing Texas speed and traffic light laws here in Montgomery County? So far, the Texas legislature has outlawed the use of cameras to enforce the speed limit. In the coming session of 2009, I expect that we will have a strong collaborated proposal to reverse this law and enable selected areas of the state to begin using the cameras for speed control in addition to the traffic signals. As you are probably aware, Montgomery County has been the leading county of Texas in utilizing the cameras for traffic light enforcement. Also, the county will greatly expand the use of cameras at traffic signals to penalize those who run the lights county-wide as deployment gets into full swing this year.

This blog will run a three month reader poll, seeking input for opinion and perceived barriers in this area. I would appreciate your comments, both negative and positive on this subject. I submit the pros and cons as I know them below.

Negative opinions

  • Invasion of privacy. A camera taking a photograph inside an automobile presents information that should not be acquired for others to view.
  • Traffic enforcement is a job for people, not technology. It takes human judgment to ascertain if a law is being violated. Minor traffic offenses are often cause to and means to discover more serious crime.
  • Traffic enforcement by fines is not effective. The fines are not harsh enough to affect a change of behavior.
  • This is just another means of taking money from the public to line pocket books with cash.
  • There is no need to emphasize traffic law enforcement. Not a threat to public safety.

Positive opinions
  • Not an invasion of privacy. Photographs taken only at a reasonable level above the speed limit (10 MPH or more) and is the equivalent of being stopped by a police officer without being stopped. Photographs not available to the public, only the processing staff and the violator.
  • Technology is now enabling the automation of traffic law enforcement. The technology is accurate, always present, and reliable. Integrated camera technology offers tax payer savings equivalent to other useful modern technologies.
  • The statistics prove that the technology is effective here in South Montgomery County. Behaviors at key intersections have changed to the good since we started issuing fines at these traffic lights.
  • Speed is excessive on our streets. Existing cameras have collected a significant amount of data showing that excessive speed is common and is a threat to the safety of our residents. On I45, the average speed is sometimes over 80 MPH. On Woodlands Parkway, the average speed is sometimes over 60 during the day and over 70 at night
  • Mobility of traffic is affected by traffic law enforcement. Every time an automobile is pulled over for a traffic violation, traffic is slowed by curious drivers. Enforcement by camera keeps the traffic moving.
  • People running lights will hold up perpendicular traffic at key intersections, causing a backup of automobiles at traffic lights. This practice has essentially been stopped at the key intersections such as Panther Creek and Woodlands Parkway where the cameras have been installed, improving the flow of traffic on Woodlands Parkway and proving the technology is doing its job.
  • Statistics reveal a higher risk of major accidents at locations where an automobile has been stopped by a law enforcement agency. There are no interruptions of traffic nor gazers slowing down the traffic when using the cameras. Data collected show that traffic movement is not negatively impacted by the cameras.
  • Financially, the county and The Woodlands will save money on law enforcement officers. In The Woodlands, we are more likely to utilize the existing officers more for crime than routine traffic enforcement. For every deputy enforcing routine traffic enforcement, it costs us about $84,000 a year, a state trooper $104,000. There is no gain nor loss financially for the county using the automated systems except for the efficiency of utilizing its deputies.
  • The primary reason for hiring additional deputies in The Woodlands was to enforce traffic laws. We had many young people being killed on our streets. As our population has grown, we have begun to experience more crime. We can expect crime to increase in the years to come. There is a need to shift the focus of traffic enforcement towards the ad hoc crimes that are on the increase, to make our neighborhoods safer without having to add more deputies.
If you know of other reasons, pro or con, please add your comments to this article. Also please place your view by responding to the poll at the upper right corner of this blog.
Related articles
  1. Montgomery County Commissioner Ed Chance
  2. Woodlands Traffic Signals
  3. Traffic Control System in Montgomery County
Postscript
Addressing the first two reader's comments to clarify:
  • The commissioner assured me that there would be no photo taken except for 5-10 MPH over the limit. He actually said 10 MPH when he was addressing the freeway issues. The idea is the same as it is for red lights. Those making minor mistakes are not the target. The target offenders are those who deliberately break the law. Slight infractions go undocumented.
  • There is a delay built into the traffic signals where the photos are taken after the light turns red, not yellow. You don't get a photo for a light turning red while you are in the intersection unless you are sitting in the intersection with the traffic stopped or nearly stopped. In that case, I don't know what happens.
  • Good point by Citizen 1001001. Every car owner in the state of Texas is responsible for what happens with that car. For example, if you permit someone to drive your car without a driver's license, you will be cited as well if that person is caught driving without a license (not sure if that happens if you are not in the car though). Since these would be essentially the same as parking tickets, the owner of the car would be responsible for the speeding and running the red light regardless who was driving.

Monday, July 14, 2008

Air Pollution Monitoring reaches out to include The Woodlands Texas


We are on the radar so to speak, to see who is regionally affected by the ozone and hazardous airborne chemicals produced by our neighbors to the South and within our own county. Today, the Texas Forest Service announced the completion of an environmental tower in Jones Forest. It is part of the Houston-Network of Environmental Towers funded by the U.S. Environmental Protection Agency (EPA) to the University of Houston. This forms "a network of meteorological and chemical sensors in the Houston area to fill in key gaps in the current State/Federal air pollution monitoring network study of photochemical smog episodes in the Houston Galveston Area (HGA)." Regionally, we in The Woodlands are a part of the puzzle. What is our exposure during major smog release events and how do we contribute to the problem? Looking outside on the parkway at about 5PM tells me that we are probably producing our share of Ozone. Developing a good understanding of photochemical smog episodes in our area is essential since not only do such events represent a health hazard, but unlike the situation in a number of other major US metropolitan areas, such as Los Angeles, where peak Ozone levels have decreased significantly, less improvement in the number of ozone exceedances has been observed in the HGA."

H-NET is currently composed of five ground-based measurement sites: University of Houston (Main Campus), Houston Coastal Center, University of Houston - Sugar Land, Texas Forest Service - W. G. Jones State Forest, and West Liberty Airport forming a virtual "box" around Houston that fills in critical gaps in the existing air quality monitoring network.

In addition to providing real-time air quality data for previously unmonitored areas, another benefit of this site configuration is for most wind directions, the network will be documenting both upwind and downwind air pollution levels. This will help the UH study team to determine how much pollution is transported into our region, and how much is produced locally. The UH Institute for Multidimensional Air Quality Studies (IMAQS) and the Texas Learning and Computation Center (TLC2) have worked together to provide a public web site for dissemination of the measured air quality data (www.hnet.uh.edu). They are using this data to evaluate and improve air quality models. It will also facilitate the assessment of health impacts of pollutants on the citizens living in the HGA. The local general public benefits directly as the web site displays in a simplified format information about wind, temperature, relative humidity, rainfall, carbon monoxide and ozone that is made available by the H-NET team on a best efforts basis.

As part of the public outreach between the University of Houston and Texas Forest Service; John Warner, urban district forester, will be conducting several Project Learning Tree (PLT) workshops for educators themed “The Air Around You”. Educators will go through a six-hour workshop to become certified in PLT. Additionally they will learn to interpret the data taken by the monitoring station so they can in-turn instruct their students.

The air quality instrumentation is located on a 300’ tower behind the Conroe office giving the camera a 360 degree view of the forest canopy and horizon. It is relayed down to the climate controlled storage container at the base of the tower where computers collect and transmit data 24 hours – 7 days a week.

Being a part of this effort not only puts The Woodlands on the map in air pollution statistics and gives us insight into our own related health issues, it also gives our forest a better chance to survive in the long term. Health is defined in several ways, not just human.

Sources

  • Dr. Berry Lefer, University of Houston – Department of Earth and Atmospheric Sciences
  • John R. Warner, CF, Texas Forest Service
Resources
  1. Texas Forest Service
  2. Gulf Star Grid - also has a weather station

Road Maintenance Technologies - Road rehabilitation in Montgomery County Texas


Montgomery County has a visionary plan to maintain our roads in a financially constrained setting. Technology offers reduced costs and improved results, so the commissioner of precinct 3 is looking at technology to provide some major assistance to reach his goals. For road maintenance and construction, there are three technologies of importance:
  1. X-ray for analysis of the pavement
  2. Low temperature asphalt for the asphalt component of the surface mixture
  3. Porous Friction Course for the surface mixture that is laid on the road
These three technologies will provide solutions to reach these goals:
  • Predict surface cracking, holes and determine road thickness on county roads
  • Develop a rehabilitation program with planning, timing of application, and optimization of the replacement area in the road and/or the complete resurfacing of the road. In other words, be more proactive instead of reactive and be smarter in planning.
  • Better optimize cost vs benefit in the road rehabilitation program
There is a need to thoroughly understand the quality and subsurface issues of the roadbed. When water is embedded within the roadbed, we have a higher risk of road surface fracture. A cavity layer with water is where the asphalt surface is the weakest. Detecting that weakness gives us insight into structural deficiencies, which will eventually lead to road failure; so by knowing this, we can prepare plans to replace the problem areas even before the failure occurs. A health check of our roads is available using x-ray technology. This method also measures the thickness of the roadbed. Data on the road is collected in a van with an x-ray system mounted on the front of the van, directionally aimed at the road surface below it. X-ray data is collected into an on-board computer and subsequently processed with computer software. Traveling at the speed of traffic, the system in the van collects the data without impeding traffic movement. Then the data is analyzed and presented in layered graphics like a seismogram to those studying the road. Montgomery county is collecting this data now in our area to assess the condition of our roads.Click here for a more in-depth explanation of the technology. Typical Scan image

In this day of higher cost petroleum-based materials, we face inflated material costs for maintaining our roads. As asphalt prices rise, the selection of materials is even more important than it was a few years ago. In the past, repair of concrete roads required asphalt to be laid at 300+ degrees. The source of the asphalt in Montgomery County is in Conroe, so the asphalt must be loaded (at 350 degrees), transported, and coordinated with the preparation of the roadbed such that is stays above 300 degrees when it touches the roadbed at the project site. Sometimes the material must be turned away, because it is too cool to put down on the roadbed. Contracts are written to assume and include this waste. To combat this issue and lower county contractor costs, the low temperature asphalt method will be utilized by the precinct. This will facilitate a lower financial risk delivery to the work site, less time that the road area is closed, lowered contractor costs, and give the work crew a healthier environment to work. For those having deeper interest of this topic, a short description of other benefits of low temperature asphalt are found at this link.

A more descriptive review of this material and case studies are found at this link.

On Rayford Road, the county has been testing a different surface technology to improve safety and provide a more durable cost effective road surface. Porous Friction Course (PFC) is an asphalt mixture with a low bitumen content (high carbon molecules which are the residues of petroleum distillation), carefully designed to provide a fast lateral water exit from the roadbed and to have strong tensile properties. The difference between a standard asphalt surface and a PFC surface is incredible. In a rainstorm, the traditional surface will require that water exit the roadway by pushing the water off, typically as a spray which hinders a driver’s vision. Combined with water, traditional surfaces also act as water slides, slippery surfaces that are a road hazards. PFC on the other hand allows the water to escape the road horizontally through porous exits pushed by both gravity and tires. This has the added benefit of combating hydroplaning issues. PFC has been known to be a weaker tensile medium with normal additives, but today’s technology has been improved to compensate for that with stronger bonding elements. I saw a video on PFC technology, demonstrating its capability. Very impressive! The video showed a road with a traditional asphalt surface. Cars and trucks were lifting the water with the resultant spray producing a foggy mist above the roadway. After the new PFC surface was laid, almost the identical conditions produced a clear road with no evidence of standing water, just an apparently wet surface. The tires were not lifting the water into a mist above the road as before. So the next time you drive down Rayford Road in the rain, you should be able to notice the difference. PFC is also a sound inhibitor. The material, also due to its porous nature, absorbs more of the noise, presumably about 3 db, not significantly detectable. Under the surface of existing roadways, I was shown the water cavities that cannot be seen with the eye. With this material, any cavities should be dry, with all the water escaping to the sides of the roadway. A well designed porous surface will therefore maintain the integrity of the road as well as provide a means for water to escape. There is a downside however. This surface is hotter in the summer and darker than concrete at night. Headlights reflect off of concrete, illuminating the road much better than with asphalt. Try this link for more information on the PFC technology.

There is some debate in the journals on what is better, rock PFC or ARFC (Asphalt Rubber Friction Course technology). ARFC has very significant noise abatement properties along with its water exit properties. ARFC lowers road noise some 13 db while the rock PFC lowers the noise by about 3db, a very significant difference. Arizona is known for its quiet highways, because they are using ARFC. I am personally hopeful that ARFC will be deployed on our roads here in The Woodlands. Related short articles to be released soon:


Saturday, July 12, 2008

Synchronization of Traffic Signals in The Woodlands Texas


Have you ever wondered why the traffic light changes from red to green, sometimes just before you get to the light? It is probably because we use traffic-actuated signals here. In The Woodlands, actuation is triggered by vehicle detection, pedestrian request, fire truck request, and timing. However the computerized decision to change the light is not as simple as it sounds.

Traffic Intersection System
Each signal location has several cameras, a control box and of course the traffic lights themselves linked to a control box. Attached electronically to the intersection control box, each camera monitors a street location consisting of one or more traffic lanes.

As you might notice, the right turn lane in one camera is not monitored and the other is monitored. That is because it is a right turn lane, assumed to not be a factor for changing the traffic signal in one, but in the other lane, an auto will affect the flow of the traffic. The boxes are imaginary boxes, nothing physical on the ground. The controller software monitors the rectangular boxes to detect an automobile. On the central control management display at headquarters and on the precinct’s web site, these boxes change color when the intersection controller detects an automobile. That color change indicates the control box has detected an automobile in the intersection. One way to check on the operation of the control system is for the traffic manager to observe these changes and see that the control system is responding properly to the movement of traffic.

The control box has a computer “brain” which is programmed to react to traffic presence situations. For example, let’s take an intersection on the Woodlands Parkway. If a car is traveling in the right hand turn lane, it is assumed to be turning to the right. If in the middle lane, the assumption is that it will pass through the intersection. For the left lane, the auto is assumed to be passing through depending on the lane configuration. And in the far left turning lane, the vehicle is assumed to be turning left. So here comes an auto in the right lane on the Woodlands Parkway and it moves to the right turn lane of the intersection. A perpendicular traveling auto is waiting for a green light at the intersection. That car now has been given priority by the computer at the intersection to receive a green light, because of these assumptions. In this case, without another automobile to consider, the computer changes the light to green for the waiting vehicle, that is, if synchronization and wait time criteria are also met. The determination by the computer to change the light is relatively simple, but is governed by several variables.

All fire trucks have priority for a green light at intersections. The truck emits an infrared light beam to tell the management system it is approaching the intersection. The system immediately responds by ensuring the light is green for the truck and red for the perpendicular traffic. A fire truck is very heavy and difficult to stop in an emergency. If it is slowed, the truck is very slow to clear the intersection because of its slow acceleration capability. It needs to proceed out of the intersection quickly so as to not impede the movement of other traffic. Police cars and ambulances are not given priority. They can move through the intersection and accelerate on by, quickly getting out of the intersection even if they have to stop.

Each intersection control box is attached to an optical fiber cable to communicate with the central control monitor and control system. Many problems with the intersection equipment can be fixed from the central location through this connection. Camera images are sent to the control center at five frames per second. In the intersection control box, the computer is able to detect automobiles in the intersection after the light changes and is able to determine the speed of a vehicle. It is able to react to these observations by signaling a photograph camera to record the event, if so programmed and the required still cameras are installed. The control system also counts vehicles moving in each direction.

Traffic Signal Synchronization
Woodlands Parkway is characterized as a “Smart Street”. All traffic is considered in optimizing vehicle flow from one point to another, and the perpendicular traffic is allowed to satisfactorily move also. This includes the pedestrian and emergency vehicles. How does the synchronization of a series of lights occur? We should know this if we are to drive through the synchronized signals without stopping.

First, the time between any given intersection and the next signal light must be programmed into the controller. The optimum velocity is utilized to time the arrival of incoming vehicles from that signal light. So typically, a velocity on Woodlands Parkway would be assumed to be the speed limit, about 45 MPH. This information usually resides in a data table. The optimum time for changing the light is programmed into the control box from that sheet. If an automobile has a reasonable acceleration from a dead stop at one traffic signal, he should arrive at the next signal light in time for a green light, at is, if he travels at 45 MPH. If he travels too fast, he arrives too early and has to stop. That may cause automobiles behind him to stop or slow down as well, so he has caused a potential bottleneck in the traffic flow.

An example of this – East Panther Creek/Woodlands Parkway intersection is considered one of the two key intersections for successfully optimizing the movement of traffic on the Woodlands Parkway. We want it to be green when we get there. We are at Six Pines heading towards East Panther Creek, passing through the light without stopping and hope to pass through the light at Panther Creek in the same fashion. That is a reasonable expectation except there may be many cars in line waiting to be released by a green light at the next intersection. Vehicles are being fed onto the parkway at Grogan’s Mill. The light will turn green in a certain number of seconds, because it is synchronized with the signal at Six Pines. If the traffic rushes to Panther Creek and stops, that traffic will not be traveling at 45 MPH for several seconds after the light turns green. The Traffic Manager has programmed this additional time into the control unit. It is assumed that a certain number of automobiles are being added to the traffic lanes from Grogan’s Mill. Now the control system at the Panther Creek intersection is told that the traffic has been released at Six Pines. The control box starts its countdown for target signal change. While it is doing that, it detects 15 cars passing through the two lanes at the intersection within the last 25 seconds. The entire situation becomes difficult to interpret, but the system has been programmed to prioritize the synchronization over the vehicle detection rate, so it goes ahead and gives the Woodlands Parkway traffic a green light after giving a red and momentarily pausing for the perpendicular traffic to clear. So the light is green for us by the time we arrive. Had a pedestrian pressed the cross walk button, we would have had to wait because the pedestrian had to be serviced within a certain time. Had a fire engine come along, we would have also had to wait. The reality of synchronization is that it may work for us sometimes and other times not. Many times, the traffic flow just cannot be predicted.

All of this becomes more complicated as we have more or less traffic entering the roadway from other locations. You can see some of the logic in the computer and how difficult it must be to get it right. The term synchronized must be regarded as a process, not an actual real thing that we can rely upon. The process only helps the traffic to flow better, not necessarily keeping every car moving from one end to the other.

If you are traveling on one of the "Smart Streets" of The Woodlands at night and wonder why you have stopped at a red light, it is likely that cross traffic triggered the signal. Synchronization is not intended for off hours. The process is intended for peak hours when traffic needs to be moved most efficiently. Soon we will add Research Forest and Lake Woodlands to the smart street inventory. Currently, only the Woodlands Parkway is synchronized.

Precinct 3 is now studying our major traffic arteries to seek better timing of the lights in the Northstar system. Lake Woodlands Drive and Research Forest will be synchronized when the traffic signals are functioning. Lake Woodlands is likely to become a 40MPH drive, higher than current limit of 35 but lower than the first predicted 45MPH, except up near the mall where it will remain 35MPH. Many thanks to both the Commissioner Ed Chance and the Traffic Control Manager Fred Koehler, for explaining how the system functions. Related short articles to be released soon:

Thursday, July 10, 2008

Northstar Traffic Control System in Montgomery County Texas


Montgomery County Precinct 3 is leading the pack in managing traffic in densely populated unincorporated areas. Our county’s progressive role in the regional management of traffic has gained much momentum. We have a state-of-the-art traffic management system called Northstar. It is really slick! Click here to see the current locations of all Northstar-managed traffic lights in Montgomery County.

Each location has one or more cameras, a control box and of course the traffic lights themselves, linked to the control boxes. The way this works is each camera monitors a street location. It determines if the light should change by several factors - detecting cars within programmed rectangles, a pedestrian-requested light change, time from last change and oncoming emergency fire trucks. This process will be more detailed in the article on traffic light synchronization.

This brings us to inter-connectivity of the intersection management system. Fiber optic cables are installed for each location. We now have 150 miles of cable supporting these systems. There is a dedicated fiber required for each control box. That is how the video is streamed to the central location at the precinct headquarters and how we are able to watch the videos from our workstations. One person is located in the control room constantly monitoring the traffic flow and overseeing the operation of the equipment. Soon there will be two persons assigned to this duty as the workload will be greatly increased.

A fiber optic feed is also provided to the county's emergency control center in case of emergency evacuations or incidents. For cost efficiency, there is an agreement to share fiber cables with TxDOT. When the county must install a fiber cable to support an intersection control system, the sharing is in reverse. Precinct 3 is now developing a loop configuration so that there is a backup communication route in case of a cable outage. This entire system will be utilized county wide as it is expanded beyond the confines of precinct 3. Several cities nation-wide are looking at the deployment in our precinct, because we have used innovative techniques to utilize the best of specialized cameras but non-proprietary computer equipment. Cost efficiency is key to the success of this county’s program for management of intersections, including the ticketing of red light offenders.

What is the future of this technology? For sure the deployment here will be expanded. Within two years, there will be 500-600 units operating in the county. Additionally, the violation cameras will be expanded to key intersections. These cameras are also capable of determining the speed of individual automobiles. If there is a speeding car behind one that is not speeding, it is possible to miss the detection of the speeding car. This is the only known flaw with the camera. Otherwise, the county is positioned to issue citations for speeding if the legislature will permit the practice. Why start issuing speed tickets by the camera method? "It is much safer than a police officer issuing a citation along the roadside where traffic movement is impeded by the issuance of a traffic ticket" noted Ed Chance the commissioner. It is the the rubberneck effect. Is there an issue of privacy? If someone is speeding (usually 11 MPH over the limit), defined by criteria for the camera’s location, the camera will set off a photo. If not, there is no photo taken. Break the law; county takes a photo – no invasion of privacy. If a policeman pulls you over for speeding, it is not an invasion of privacy. See the commissioner’s comments on his who’s who page.

When accessing the Northstar website, you can watch any particular intersection you wish. The data is streamed to you at one frame/second. At headquarters, they watch it at 15 frames per second. To view an intersection, simply click on the location on the map that you wish to see. You may have to scroll on the Google map to find the intersection you wish to view. To do that, click and hold down the left button of your mouse over the map and move the map until you see the intersection that you seek.

Weather stations are also being planned for the Northstar system. Bridges sometimes ice up and other times do not, when under a freeze advisory. It would be more cost effective to monitor the bridges electronically for a near freezing temperature and then deploy surface crews, rather than deploy them each time the weather might be freezing. In other words, just in time cost effective ice prevention on each bridge. This is part of the near term planning of the precinct.

Some related statistics might help us to understand our issues and the need for automation. On some days, East Panther Creek and Woodlands Parkway has as many as 75,000 trips logged, a very heavy load. Woodlands Parkway has some 50,000 trips per day as an average. Our intersections are designed for 1900 cars per hour. We exceed that significantly at East Panther Creek and Gosling intersections with Woodlands Parkway. For every automobile running a red light, we have an additional 9 seconds delay for the perpendicular traffic. If 10 automobiles continue through an intersection after the light changes, they have caused as much as a 90-second additional bottleneck for perpendicular traffic.

Traffic speed statistics are regularly gathered in 15-minute windows. On I-45, the average speed of vehicles has been measured as high as 81 MPH in one of these 15-minute windows. Assuming some of them were traveling at 70, then some of them were also traveling at 90 or even 100! On The Woodlands Parkway, peak speed average is a little over 60. That means some traffic is likely moving at 70 MPH or more.

Also noteworthy, we have fewer automobiles on our roads this year than we had last year. This downward trend is what we are looking for. Research Forest and Lake Woodlands expansion projects should continue that load reduction trend on the Woodlands Parkway.

Related short articles to be released soon:

Many thanks to Commissioner Ed Chance and Traffic Manager Fred Koehler for their time to explain the vision of the precinct and county.