Smart Corridors use technology to alleviate congestion

TML Communications Specialist

As technology evolves, transportation officials across the country are looking at ways to make commutes faster and easier, especially on major and frequently-congested corridors.
One emerging tool is the Smart Corridor, a section of roadway featuring specialized signage that can alert motorists to upcoming accidents, weather events, and other obstacles. The goal of the technology is to help transportation officials’ better guide motorists by using strategies to alleviate congestion.
Atlanta recently broke ground on a new Smart Corridor in its downtown and the city of Pittsburg, Pa., is partnering with the Pennsylvania Department of Transportation for a $30 million smart-signal system. Similar plans have been discussed for Austin, Texas, and implemented on a small scale in areas like Denver, Chicago, and in the Minneapolis-St. Paul, Minn., area, largely on major interstate corridors.
The greater San Francisco Bay area implemented a $79 million Smart Corridor system in the summer of 2016 along its Interstate 80, which has served as the test case for many other areas. Consistently named as the worst-congested corridor in the country, this stretch of I-80 transports some 270,000 vehicles daily with an accident rate twice that of the state average.
The Nashville and Memphis Metropolitan Planning Areas have already looked into Smart Corridors as solutions to traffic congestion in the area. The state of Tennessee is also looking into these corridors for Interstate systems.
Phillip B. “Brad” Freeze, director of the traffics operation division of the Tennessee Department of Transportation (TDOT), said Smart Corridors are one way transportation officials across the country are looking at using technology to make transit easier and more reliable.
“A Smart Corridor is us learning to operate a corridor more efficiently through partnerships and through the use of technology, both existing and future, emerging technology,” he said. “Smart Corridors are really targeted toward congestion as a result of non-reoccurring causes, which include instances like traffic crashes, weather events, and anything that is not planned. If you look at information from the Federal Highway Administration, 60 percent of the causes of congestion are the direct result of these non-concurrent incidents.”
While increasing the capacity of roadways may seem like a good solution to easing congestion, Freeze said congestion management is more efficient.
“You aren’t fully addressing the project by just adding another lane,” he said. “You have to make the system work more efficiently. You can’t build your way out of congestion. A major expansion project, like adding a couple of lanes to I-24, would take at least 10 years from planning to design to the environmental processes before you can even construct it, which can take three years or more. We can do things now that directly impact the causes of congestion.”
While it may seem inevitable, Freeze said rush hour traffic is one of those unplanned occurrences. One of the goals of Smart Corridors is to provide more predictable travel times.
“Rush hour is really influenced by traffic incidents,” he said. “You have a limited capacity out there and your road system is operating at or near capacity, so when you have an accident it really compounds the issue. What we want to target is how reliable the system is, and how reliable it is from day to day. You can’t plan your day around rush hour, and that is what we are trying to target: that unreliability.”
Smart Corridors allow transportation officials to communicate more and better information to motorists as well as have more control over traffic.
“It helps reduce accidents, even the flow of traffic, reduce the buildup of congestion, and makes the system a little more reliable,” Freeze said. “It allows other strategies that allow dynamic speed control where we can adjust speed limits or advisory limit of speeds to slow down the flow of traffic. It sounds counterintuitive to slowdown the system to speed up traffic, but it actually works. We can let people know if lanes are closed ahead and control when people start to merge over into another lane.”
These corridors can also make things easier for emergency personnel responding to traffic incidents, Freeze said.
“Part of the process is working together with first responders and creating better response plans,” he said. “We want to make these roadways safer for first responders to do their jobs.”
The technology used by Smart Corridors is similar in display to the dynamic message boards already located throughout interstates in Tennessee as well as the technology used by TDOT’s SmartWay app, which gives mobile and desktop users current updates on traffic speeds, delays and construction zones.
While most Smart Corridors are planned around one major roadway, Freeze said integrating arterial roadways are an important part of these projects.
“When we say Smart Corridors, we talk about using freeway systems but it also includes the adjacent arterials off those when we have a major incident off the interstate,” Freeze said. “Those arterials can provide diversionary routes for some of the traffic. We want to provide better synchronization of the signals on arterials along those corridors, and better response plans for those signals so those roads can better handle an influx of people and how we move them.”
Interstate 24 between Murfreesboro and Nashville has been considered as a Smart Corridor pilot program area for the state of Tennessee with the project eventually expanding to other corridors in the state. Freeze said the state has already expanded its systems in this area, including monitoring cameras and dynamic sign boards, as well as expanding highway service patrols in the area. Freeze said one of the challenges is the ages of different systems on the corridor, but the hope is to begin implementing more technology strategies in the long-term.
While most may think major metro areas are the only regions up for consideration for Smart Corridor projects, Freeze said this isn’t so. Other areas considered for Smart Corridors by the state include Interstate 40 in Jackson.
“These concepts work in all areas,” he said. “Jackson has eight or nine exists on I-40, and it can get quite clogged in that area during lunch hour and morning peak. These strategies aren’t just good for larger urban areas. They can have effects on these areas as well. Smaller areas may not need all the components needed in an urban area, but these strategies can be useful for them. A lot of areas of the state have periods when traffic is a big issue.”
Another goal of Smart Corridors is to adapt as transportation technology evolves as well. The emergence of “connected vehicles” with access to cellular communications, internet, wi-fi and other technologies may even allow for transportation departments to receive and disseminate information to motorists in the future.
“One of the things about Smart Corridors is planning for things like that happening in the future,” Freeze said. “Smart Corridors are about integrating corridor management, and are an all-encompassing concept. It is about all we can do to make the system work more efficiently.”