Installation of a traffic signal system that can automatically adjust lights to meet demand will be delayed until after several road projects on U.S. 29 are completed in 2017.
However, the Virginia Department of Transportation will upgrade existing signals in the corridor before construction begins next year to allow traffic engineers to adjust the lights remotely.
“Our goal as traffic people is to get something out there in advance of all these construction projects,” said Teresa Gardner, regional traffic engineer for VDOT’s Culpeper and Staunton Districts.
“From our perspective, we need to manage that corridor during construction and ultimately manage it when construction goes away,” she added in a briefing Wednesday to the Albemarle Board of Supervisors.
Rhythm Engineering’s InSynch technology was installed at several intersections on U.S. 250 on Pantops in November 2011 as part of a pilot program. After seeing data that indicated the system helped improve traffic flow, then-Supervisor Dennis Rooker persuaded the board to commit county dollars to installing the cameras and related hardware on U.S. 29.
The system was supposed to be installed by the end of this summer, but a recent decision by the Commonwealth Transportation Board to invest more than $200 million in projects related to U.S. 29 is among the reasons why that will not happen.
VDOT has begun a process to select a contractor to design and build a $81 million interchange at Rio Road and U.S. 29, a $54 million extension of Berkmar Drive to Hollymead Town Center, and $51 million to widen U.S. 29 to six lanes between Polo Grounds Road and Hollymead Town Center.
Additionally, construction of the so-called Best Buy ramp in Charlottesville is expected to begin sometime next year.
“No one in the world, as much as we want this to happen, wants us to put up something we have to tear up during construction,” said Supervisor Ann H. Mallek, a supporter of the project.
Gardner said the existing signals have to be periodically retimed by engineers in the field, and cannot be programmed remotely.
“If there’s an incident, a weather event, or a big sale at Kohl’s, [the system] does not have a way to adjust in real time,” Gardner said.
Rhythm’s InSynch technology responds to changing conditions by being able to see an entire system as a whole. Lights are adjusted by an algorithm that turns signals green when the system sees openings.
However, Gardner said the system may have trouble responding during peak hours when roads are “over-saturated’ with drivers.
“We want the public to understand that this is not an answer to everything,” Gardner said.
Gardner also said the system also can fail if camera footage cannot be relayed to the rest of the system. To minimize those failures, the U.S. 29 system will use fiber-optic cables that are in the corridor in most places. However, sometimes there can be glitches in the system.
“Pantops has failed a few times, so if you sat in delays, that was the failure to the processor,” Gardner said. “Sometimes when it fails, it can create serious safety issues.”
For instance, a recent failure in Winchester kept the lights on U.S. 50 on red while side streets were all green. This persisted until a technician could be dispatched to the site.
Gardner said the failures are increasing and VDOT does not know why, but that InSync is working to improve their software.
Supervisors wanted to know who would be responsible for damages that might be caused in the event of failure.
“If we had a situation on 29 where everything was red except side streets for two hours, we’d have to mobilize our police force to be out there, and we’d like to be able to send the bill to someone,” said Supervisor Jane Dittmar.
Gardner said VDOT’s contract with Rhythm Engineering is being renegotiated and she will try to get that concern addressed.
In the meantime, Gardner said her team hopes to improve the existing traffic signals before road construction begins near in order to allow VDOT to control signals in real-time.
“That means updated controllers along the corridor that can take data,” Gardner said.”
“This would put the communications in place so the signals talk to each and talk back to our traffic operations center and system engineers.”
The adaptive technology will not be added until the first phase of U.S. 29 projects is complete. That will give InSynch more time to work out the hiccups in its technology.
“We would then purchase the equipment and install it,” Gardner said.