5 things to know about new on-ramp signal lights on I-540

RALEIGH, North Carolina (WTVD) -- DOT Traffic Engineer John Sandor took a few minutes to answer our questions on how the new on-ramp signals along I-540 will work. Check out our I-Team story from last week for background on this project.

Here are excerpts from our Q&A with Sandor:

Q: What time will the ramp lights be turned on?

A: There really is no time. It'll be day-to-day and it's all up to a computer. "It's going to be pulling in data from the road and all the traffic out there, so it's going to go on when it perceives the need is actual there to turn itself on. We've put in a bunch of sensors out there and it's always going to be processing that data and crunching those numbers to determine when it wants to go live and when it wants to shut off."

Q: Is this project expandable?

A: Absolutely. "This is kind of our pilot project for North Carolina. We're deploying these signals along these ramps and the plan would be more to come. It's a quick thing to get out, low cost, and it does, based on the national studies, it does yield some positive benefits. We've got a list in the Triangle of potential candidates going forward

Q: What about the concern that the lights could back up connector roads?

A: It's real. In fact, the DOT shares the concern. "We do anticipate some impact on those arterials. We'll be watching that very closely as these things come on line to see what those impacts are going to be and what the perfect balance is between those streets and the highway. What we're hoping to see is while there could be an increase in travel time along those corridors getting to the freeway, once they get on the highway, the net gain will be an improvement. They'll save time on the freeway."

Q: Will these lights lead to real, meaningful change in people's commute times?

A: Probably. It's worked in other states and cities. "That's the hope; that we will see constant flow along 540 so drivers might have to slow a little bit but nothing like today when they have to stop and crawl all the way to 70. Our hope is that they maintain some type of speed through this entire corridor."

Q: What about potential rear-ends and other "stop and go" accidents?

A: The DOT's not too concerned. "You see these cars getting on the on ramp, they're going at a lower speed; so the hope is the drivers are going to be paying attention. We've got flashers here to warn them in advance, the signals are active so slow down. And, of course, the tradeoff will be less rear ends on the interstate. Hopefully the traffic will be moving through there so hopefully we'll see safety improvements on the highway."