Even in a region where so many commuters endure long and unpredictable trips, I-66 stands out. In fact, it’s one of the most congested highways in the nation. The bottleneck just west of the Capital Beltway is severe, but other choke points occur in Rosslyn, near the junction with Route 267, near Route 50 and near Route 28.
There has been some traffic management. Outside the Beltway, the far left lane is under HOV-2 rules in the rush-hour direction. Inside the Beltway, both lanes in the rush-hour direction are HOV-2. The Virginia Department of Transportation also opens the shoulders to through traffic west of the Beltway during rush hours. It’s still not enough to handle the demand. So VDOT is saying it wants to actively manage the lanes through technology upgrades.
Above all, VDOT wants to make the highway safer by reducing the number of crashes, but the active management program could also make trips more predictable and perhaps even ease the congestion.
The $32 million program (90 percent of the money would be federal funds) involves hardware, software and humans. The humans managing the program will be at the McConnell Public Safety and Transportation Operations Center in Fairfax. Most of the other humans needed to make this work will be driving on I-66.
Hari K. Sripathi, VDOT’s regional operations director, said that while the sensors, lane controls and information displays involved have been used elsewhere, this new program is being designed to fit the needs of I-66. Drivers in different areas between Haymarket and the Potomac River will see differences in its applications.
Farthest west, between Routes 15 and 29, the program will expand the use of traffic cameras, information displays and sensors measuring speed and congestion. East of that zone, drivers between Routes 29 and 50 will enter a zone of active traffic management, with a lane control system mounted on gantries above the highway and information displays that can warn about conditions ahead.
Between Route 50 and the Beltway, the program adds a monitoring system for the shoulder lanes and a monitoring system for the emergency pullouts. Use of the shoulder lanes, now fixed to certain peak hours, can be adjusted to meet changing demands. Assistance can be sent more quickly to disabled vehicles parked in the the pullouts.
Inside the Beltway, VDOT will use traffic cameras, message displays and sensors. The ramp meters, those red and green lights at some I-66 entrances, will be smartened up. Now they’re on automatic cycles, intended to space out the rate at which vehicles join the crowd on the highway. Smarter versions could be adjusted to fit conditions, on the interstate ahead or toward the back of the line on the ramp.
Inside the Beltway, where Route 267 and eastbound I-66 meet, VDOT also is considering use of a “dynamic merge” system. Based on information from roadway monitors, the message signs and lane indicators can warn drivers to slow down or to control lane use for a smoother merge.
The active management system isn’t scheduled to be up and running until summer 2014, though some elements might be introduced earlier. The planners and engineers still are studying how to make best use of the hardware and software on the individual segments along this 34-mile route.
It’s a lot of information. In some sectors, the gantries will be placed about every half a mile. Sometimes they’ll deliver good news, reassuring drivers that the road ahead is open and they don’t need to seek alternatives. But often it will be bad news, accompanied by warnings to slow down and to change lanes.
Success depends in large part on drivers acting on those instructions.
When an accident occurs, the active management system creates several opportunities. The message system can warn drivers approaching the crash that they need to slow down well before they encounter stopped traffic ahead. That reduces the chances that other crashes will make the congestion even worse.
When emergency equipment approaches, the managers in the operations center can switch on the red X’s over the lanes they need to clear so the first responders can reach the scene. That could create a half-mile or more of clear lane space for the responders.
But picture it: The two right lanes, covered by red X’s, might be clear of traffic up to the crash scene. The traffic squeezing into the two left lanes is stop-and-go. Imagine what can happen as some of those stalled drivers eye the open pavement to the right. Oh, what would it hurt if we just jump the line a little? Nobody seems to be using that pavement right now, and we really can’t afford to be late.
Sripathi is wise to the ways motorists behave. This isn’t just about technology, he said. It involves a different way of thinking about traffic, not only on the part of the traffic managers but also on the part of the drivers being managed.
“The system has such a great potential,” he said, but public acceptance is important. “We need to have that conversation with the general public.”
While the plan is coming together, many decisions about how exactly it will work are yet to be made. This week, the public will have a chance to learn about it and to begin that conversation Sripathi talked about. A public information meeting is scheduled for 5 to 8 p.m. Thursday at VDOT’s Northern Virginia District Office, at 4975 Alliance Dr. in Fairfax. A brief presentation will begin at 6 p.m.