County builds future-ready transportation IT network
Gwinnett County’s Transportation Department tied its upgraded network more closely to the county’s enterprise IT infrastructure, allowing standardized technology and paving the way for connected vehicles.
With more than 2,650 miles of roadway to manage and a population that has almost doubled over the past 20 years, Gwinnett County, Georgia, faces the challenge of keeping traffic moving while maintaining its IT infrastructure.
An added complication is that the Gwinnett Department of Transportation operates its own IT network with its own vendors, separate from the county’s enterprise system. But when DOT’s existing network switches began to reach end of life, county officials had the opportunity to standardize some equipment across both networks and further embrace intelligent transportation systems (ITS) network technology.
The upgraded network uses ruggedized industrial switches from Cisco, which is already a partner on Gwinnett County’s enterprise IT network. By using one set of switches across DOT’s and the county’s IT networks, updates and security patches are easier to manage, saving both staff time and taxpayer money.
The ITS technology means DOT staff can respond more quickly to signal outages, change signal timings in real time to aid traffic flow and warn road users of upcoming obstacles like road construction with electronic signs.
For example, the software automatically reports signal outages via an email notification sent through the network, rather than having to be called in by someone physically looking at the malfunctioning signal. Or it means that traffic volume can be measured regularly and signal timings adjusted accordingly, rather than once every couple of years by engineers placing rubber traffic-counting strips on the roadway.
“Ultimately, the residents see better running traffic signals,” said Ken Keena, traffic management systems section manager for Gwinnett County. “Better traffic flow is the bottom line, but working your way back, it's because we're able to manage the signals consistently, because we have a consistently up network that's secure and maintained.”
Defining boundaries between the county and DOT networks has been critical, Keena said, although he noted it has not required “formal” paperwork or a memorandum of understanding, but instead consistent communication between both departments. In this arrangement, Keena said DOT manages Layer 2 of the network—data transfer between nodes—while IT manages Layer 3: the network layer.
“We're not network engineers,” Keena said. “We don't want that responsibility or to have to gain all that knowledge. We'll leave it to them, who are the experts, so we drew that line and it's been working really well.”
Having a city or county IT department manage an enterprise network as well as cybersecurity, emails and data centers while other agencies manage operational technology is “not an uncommon environment,” said Kyle Connor, internet-of-things business development director at Cisco. It can create two different networks, so it can be tricky to manage without true collaboration, he said.
“Because of the needs of the agencies, they start plugging [the networks] together unbeknownst to each other, which causes network confusion,” Connor said. “It creates issues if you're trying to cybersecure the network and you're not sure what's getting plugged into it, how, where and how.”
Installing the new switches slowly started rolling out in projects along two transportation corridors, totaling about 30 or 40 switches, which then needed to be strategically configured. Transportation engineers were unfamiliar with the switches’ programming language, but their counterparts in IT knew it, so Keena said DOT “really drew on their expertise.”
The upgraded network also will support signal preemption for emergency vehicles and signal priority for transit, Keena said. It also will help Gwinnett County prepare for an influx of connected vehicles, which communicate with roadway infrastructure including traffic signals and control boxes, as well as with each other.
And while there may be some edge computing required to support those upcoming initiatives and processing the data they create, much can be done on the current network. “I think we've future-proofed pretty well; we have a pretty robust network,” Keena said.