In July 2013, Rob Klug was at an IMSA conference in Phoenix, Arizona when a major overlay project began on one of Clark County, Washington’s principal arterials. The road overlay project required the closure of a freeway interchange and a principal arterial with several major crossings. A radar vehicle detection system was installed and operating the week before the grind and overlay occurred; on the morning the roads were reopened to traffic, Klug sat drinking coffee in his hotel’s restaurant, using the hotel’s Wi-Fi and his laptop to verify that all of the lanes were working properly. Thanks to PTZ camera footage and data from SmartSensor Matrix, Klug was able to monitor the system from more than 1,300 miles away.
This is a very different scenario than what Klug experienced when he first began working as the traffic signals manager for Clark County Public Works. Traffic signal systems that were considered state-of-the-art in the 1980s have become dated and obsolete, and for the past several years, Klug has been on a mission to update the Clark County system by replacing older devices with more sophisticated modern technology.
This has also meant a change from traditional embedded loops to non-intrusive radar detection, but Klug says the change has led to improved intersection safety. In 2014, Clark County Public Works was recognized for its signal optimization project and the effort that has been made to make these intersections safer. To date, Clark County has seen a 30 percent reduction in collisions at updated intersections, and the improved safety and efficiency has helped the county leverage additional grant money for even more improvements.
Like many agencies, Clark County Public Works has experienced ongoing issues with loops: the manner in which loops are installed in the pavement, combined with the county’s reliance on contractors for all loop installations, have resulted in long, drawn-out maintenance and replacement projects. According to Klug, the process to replace damaged loops can take up to four months in certain weather conditions in the county.
About seven years ago, Klug set out to find a reliable, non-intrusive detection system. The county first tried video detection and found traffic cameras had improved over the years but still had some problems. Then, just a year after giving cameras a try, Klug discovered Wavetronix radar and believed he had found the non-intrusive solution he had been searching for.
The first deployment of Wavetronix radar in Clark County consisted of a single SmartSensor Advance unit installed temporarily during a repaving project.
“The Wavetronix SmartSensor Advance detector looks for groups of cars coming and will keep the signal green for longer periods of time and will also look to see if any car is in a dilemma zone,” says Klug. If a vehicle is detected within a dilemma zone, the light can hold the green until the car has safely passed, “so you won’t have that panic stop where you don’t know if you should stop or go.”
The grind and overlay project required the removal of loops from the main street’s left-turn and through lanes. In the past, when loops were removed during repaving, traffic signals would be left in maximum recall, often for several weeks, in order to compensate for the loss of detection. Max recall provides time for left turns and other movements, even when there isn’t any traffic. Klug says that, in general, leaving a major intersection in max recall for multiple detection zones would result in five to 10 calls per day from highly aggravated drivers who did not like waiting so long at a red light.
SmartSensor Advance allowed Klug to place the signal in minimum recall for the main street’s protected left-turn and through lanes. “We worked extensively with the Advance software to set up multiple zones and speed traps to trick the signal into holding the left and through movements to make the signal work,” Klug says. The signal worked so well, Klug and his team received absolutely no calls complaining about the signal during the entire three-week project.
“If I do my job right, nobody knows I exist,” Klug says.
That early Advance installation proved to be very successful, so when Klug was first introduced to SmartSensor Matrix, opting to try it out was an easy decision to make. In early 2011, Matrix was installed at three temporary, span-wire traffic signals as part of a major construction project, which included major modifications to one intersection – effectively doubling it in size and raising the entire intersection by four feet in elevation. Matrix was installed parallel to video detection systems to allow for movement of detection zones as construction phasing altered the position of the lanes of travel.
Klug was able to communicate with each sensor from the county’s internal network via cellular data modems. At one point during the project, Klug was visiting family in Idaho when he received a work call from the construction inspector who notified him that the detectors at the intersection were not working properly. The inspector requested that the problem be fixed as quickly as possible, so Klug opened his laptop, connected to the local 3G network, and within three minutes was communicating with the Matrix sensors at the intersection in question.
Klug could quickly see that the contractor had moved traffic 30 feet to the right of where it had been the last time he had looked at the intersection. Klug confirmed with the inspector that the shift in traffic had occurred earlier that same day. Within seconds of moving the detection zones and reconfiguring the sensor, the signal was working properly again.
“The Matrix SmartSensors worked so well that we decided to install Matrix at several of the other intersections that we were building,” Klug says. “Matrix is now the standard for stop bar detection at new intersections and we are installing it as quickly as possible at existing intersections.”
For the last couple of years, Clark County Public Works has installed SmartSensors Advance and Matrix ahead of grind and overlay projects, allowing them to decommission old loops before any pavement is cut. This new method makes it possible for detection zones to be adjusted to meet striping modifications or lane shifts that result from the road work.
In 2013, Clark County required pavement contractors to install and fully operate radar detection prior to doing any work that would damage existing loops. The longer turn-around time caused some problems with project delivery.
“We addressed this in 2014 and 2015 by letting an early contract to install the radar systems very early in the year, followed later by the overlay project,” says Klug.
And Klug hasn’t limited himself to just Advance and Matrix. Clark County Public Works also operates 28 SmartSensor HD freeway count stations, each communicating via Ethernet to a server running Wavetronix DataView and Collector software. It hasn’t always been this way; Klug says several other count stations were tried before the county chose to use HD.
“One company claimed in its catalog that it could take inputs from a NEMA TS1 detector to drive the counts,” says Klug. He verified this with the owner of the company, but after several stations had been installed, Klug determined this wasn’t going to work.
“Knowing products will work exactly as advertised is significant."–ROB KLUG, TRAFFIC SIGNALS MANAGER, CLARK COUNTY PUBLIC WORKS
“They required that you use their own internal loop algorithm, and they had added some contact closures, but never actually tested them on a NEMA or Caltrans TEES-style loop detection output,” Klug says. “The reason we didn’t want to use their internal loop detection was that the induction loops met the NEMA standards, but had too high of inductance to work within their own internal loop detection hardware.”
After working with that company for over a year, the company gave up and walked away from the project. Previous problems and unpleasant experiences like this have helped Klug appreciate the customer service Wavetronix provides for all of its products. “Knowing products will work exactly as advertised is significant,” Klug says.
“Matrix is now the standard for stop bar detection at new intersections and we are installing it as quickly as possible at existing intersections." –ROB KLUG
On the back end, Clark County uses Collector software to bin count station data every 24 hours; the data is then pushed to Portland State University’s data portal. Later this year, the county will begin using Translator to feed live data to the portal via an XML output, so the information will be real-time instead of a day old. Translator simplifies data distribution with automated, immediate conversion between incompatible formats and databases. The new module will include custom software written by Wavetronix that will incorporate the HD count stations on the freeway.
Additionally, Trafficware will write custom software that will incorporate Translator’s feed in to the Naztec ATMS Now central system. This system will monitor freeway traffic speed, occupancy and volume in addition to traffic detected on freeway off-ramps.
“If the system detects that a freeway incident has caused traffic to spill over onto the parallel county arterial network, the central ATMS traffic responsive system will place specific intersections into a special plan to allow for the extra traffic,” Klug says.
The lofty goal of modifying the entire traffic system in Clark County is what Rob Klug and his team have devoted their efforts to, and the state of Washington is paying attention to the impressive countywide network. Last year, the Clark County Public Works received a Target Zero award from the state in recognition of the safety and efficiency improvements they have made by updating their traffic signal systems. Now, radar detection is being asked for by signal technicians throughout the area, which is something that has impressed Klug. The results so far have been very positive, and will lead to future installations of Wavetronix radar at new projects and in place of old loops.
