An engineer, a physicist and a mathematician were each given $150 and were told to use the money to find out exactly how tall a particular hotel was. The physicist bought some stopwatches, a number of ball bearings, a calculator and got some friends together. He had them all time the drop of ball bearings from the roof and then figured out the height from the time it took the bearings to accelerate from rest until they hit the sidewalk.
The mathematician bought a protractor, plumb line, a measuring tape and a scratch pad. She waited until the sun was going down and then measured the length of the building’s shadow, found the angle the roof made from the ground and used trigonometry to figure out the building’s height.
The next day, these two bumped into the engineer and asked how he found the height of the building. He replied, “I gave the bellhop five bucks and asked him how tall the hotel was.”
Using existing tools in unexpected ways to solve problems is the hallmark of a great engineer. Especially in the traffic industry, where funding is always an issue, making innovative use of proven and existing tools can mean that some especially pernicious problems can be solved in ways that are as reliable as they are innovative.
When it comes to traffic solutions, the foundation of any system has to be reliable vehicle detection. In this arena, Wavetronix SmartSensors are proven to be the gold standard: SmartSensor HD is the only vehicle detector with patented true high-definition, dual-beam radar, providing the most accurate vehicle data for ITS and planning applications; SmartSensor Matrix uses high definition, multi-beam radar and a patented radar imaging process to see all vehicles at the intersection, moving or stopped, even in difficult conditions; and SmartSensor Advance uses patented dynamic ETA tracking to continuously monitor the speed and position of individual vehicles approaching the intersection, providing dilemma zone protection to all vehicles that need it.
It’s one thing that these tools exist; it’s another thing all together that traffic engineers around the world recognize the power of SmartSensor products and utilize them in innovative and surprising ways to solve some truly wicked problems. Over the next few issues of Pulse we will highlight some of these innovative solutions.
This issue focuses on the Lone Star State. With more lane-miles of roadway than any other state in the US, Texas is a leader in embracing advanced technologies to address serious, often dangerous traffic challenges. Working with other agencies and Twincrest Technologies, an authorized Wavetronix channel partner, the Texas Department of Transportation is using SmartSensors to solve these problems in extraordinary ways.
Wrong-way drivers are a huge problem all around the world. In the US, wrong-way driving accounts for three percent of all accidents, and these accidents have a fatality rate 27 times higher than other kinds of high-speed crashes, according to the US National Transportation Safety Board.
In Texas, 30 people were killed in wrong way-related traffic accidents between 2007 and 2011; in San Antonio alone, TxDOT recorded 185 individual events involving wrong-way drivers in 2011, resulting in seven fatalities. In August 2014, a wrong-way accident in Harris County, Texas killed five people, including a three-year-old child.
Traditionally, TxDOT relied on 911 calls to inform the agency of wrong-way drivers so countermeasures could be engaged. This system was problematic because it can take several minutes for a 911 call to be placed and processed — long enough for an accident to occur.
In order to more effectively combat wrong-way driving, a multi-agency task force was formed, which included TxDOT, the Federal Highway Administration, the Texas A&M Transportation Institute (TTI) and the San Antonio Police Department. Using SAPD and TxDOT’s TransGuide logs, and spatial analysis technology created by TTI, the San Antonio Wrong-Way Driver Task Force identified a 15-mile (24 km) stretch of highway 281 as the most problematic, and piloted a system that uses SmartSensor HD for vehicle detection.
The system includes Doppler detection on exit ramps and SmartSensor HD detectors on the highway. When a vehicle enters an exit ramp, the Doppler devices trigger a flashing wrong-way warning sign; on the freeway, if HD detects a vehicle traveling in the wrong direction, it activates a blank LED sign that displays a message to the driver. A message is also sent to TxDOT’s San Antonio center, and authorities are dispatched. HD’s unique dual-radar design allows it to accurately detect a vehicle’s direction of travel as well as its speed.
The pilot project, which took place in 2012, successfully reduced wrong-way driving events by approximately 30 percent. According to the task force, SmartSensor HD will be used in similar deployments of the system.
Wrong-way driving accounts for three percent of all accidents [in the US] and have a fatality rate 27 times higher than other kinds of high-speed crashes.
Truck rollovers are a common problem, especially with interstate on- and off-ramps. The National Transportation Research Institute recently released a five-year analysis for truck rollover accidents across 31 states and found that Texas was at the top of the list as far as numbers of accidents. During that five-year period, 31 people died in truck rollover accidents in Texas.
Another study, this one from the Association for the Advancement of Automotive Medicine, analyzed what caused truck rollover crashes. They found that almost half of rollover crashes resulted from failing to adjust speed to curves in the road on on- and off-ramps. The second most common cause came from inattention from the driver.
In Houston, TxDOT recognized there were a number of tight interchange connector ramps where truck rollovers were fairly common. Working with TransCore and Twincrest Technologies, TxDOT utilized SmartSensor HD in a system that combats these two most common causes of truck rollover accidents.
According to Magdy Kozman, transportation operation engineer for TxDOT, a system was created where HD units are used to measure an approaching truck’s speed and vehicle length. If the truck exceeds a predefined speed and length, warning lights will flash encouraging the truck driver to slow down. In addition, because HD’s dual-beam design accurately detects the true speed of individual vehicles, the truck’s actual speed can be posted on an LED speed sign.
Previous systems utilized inductive loops to gather the vehicle information, but loops were difficult to maintain and often needed replacing. Kozman said installing HD sensors reduced maintenance and replacement costs and reduced installation costs because HD does not require lane closures to install, unlike loops.
The system helps reduce truck rollover accidents by forcing a driver’s attention to the existence of the tight curve and the truck’s unsafe speed.
When freeways around Houston become crowded, motorists naturally divert to less-crowded frontage roads. These roads have signalized intersections that traditionally have been controlled by time-of-day programs, which allow more green time during anticipated rush hours.
These systems fall apart during unanticipated times of heavy congestion such as weekends, holidays and vacations. Likewise, and perhaps more importantly, the system doesn’t work during times of emergency, including times when hurricane evacuation plans are in effect or when accidents on the freeway cause traffic to divert to the frontage road. The end result is gridlock on both the freeways and the frontage roads alike.
Steve Chiu, an engineering specialist for TxDOT, is in charge of a project to help alleviate this problem. TxDOT utilizes SmartSensor HD on the freeway to control timing schemes for frontage road intersections. HD accurately monitors freeway conditions for up to 22 lanes of traffic, allowing the new system to measure freeway capacity.
Once a certain threshold is reached, HD triggers a contact closure from a Wavetronix Click 513 radio at the sensor’s location to a traffic signal cabinet, which initiates a preprogrammed timing pattern. This pattern allows traffic to flow more smoothly through frontage road intersections.
An initial pilot system on highway 290 west of Houston used one freeway sensor to control three frontage road intersections. The success of this pilot led to a second installation on highway 10 west of Houston, where three freeway sensors control six frontage road intersections.
“Wavetronix was chosen for this project because it has the most capable and complete selection of equipment that meets the need of the freeway adaptive system and it is the most reliable and user-friendly system,” Chiu says. These examples are only the beginning. All over the world, traffic engineers are using SmartSensors to create effective, innovative solutions to some of the most wicked traffic problems. Stay tuned in future issues of Pulse to hear more of these stories.
