DOT: On-ramp signals could help ease congestion on I-540

Posted April 7

— As the North Carolina Department of Transportation continues to look for new ways to ease congestion on some of the Triangle's busiest highways, a lane closure planned for this weekend will offer a bit of insight on what's to come for the state's first ramp-signal project.

Weather permitting, crews will shut down Interstate 540 West at Leesville Road at 9 p.m. so crews can widen the existing ramp and resurface it, install guardrail and temporarily stripe new pavement.

The ramp should reopen by 6 a.m. Monday.

DOT: How on-ramp signals work

On-ramp signals, also known as ramp meters, are stop-and-go lights on highway entrance ramps.

They work like traffic signals. When activated, vehicles on the ramp must stop when the light is red and wait a few seconds until it turns green before entering the highway.

DOT: On-ramp signals could ease congestion on I-540

The meters allow one of two vehicles to merge at a time, spacing out the number of cars entering the highway to create better traffic flow.

DOT officials say they hope to begin using on-ramp signals by September in the following locations on I-540:

  • Falls of Neuse Road (Exit 14)
  • Six Forks Road (Exit 11)
  • Creedmoor Road (Exit 9)
  • Leesville Road (Exit 7)

DOT: On-ramp signals could ease congestion on I-540

According to a DOT officials, on-ramp signals have worked in other metro areas.

DOT officials say they resulted in a 22 percent decrease in travel time during peak hours in Houston and a 16 percent decrease in the crash rate during metered hours in Phoenix.

According to the same study, peak congestion lasted 44 minutes on Leesville Road in 2011. That grew to 73 minutes in 2013.

"As commuters know, especially in the morning on the westbound side, things get very congested," DOT spokesman Steve Abbott said. "Coming down the ramp, you may have a pile of cars, and all of a sudden they're merging in all different places."

The state is also evaluating on-ramp signals for Charlotte-area interstates.

Officials say the signals can be activated at any time in response to unusual circumstances – such as special events and collisions – but typically, their use will be limited to peak periods, such as morning and evening commutes.

"Obviously, it's intended for rush hour, but we can use it if there's a crash up ahead to limit how many cars get on the road," Abbott said.

During this weekend's closure, drivers can access westbound I-540 by driving east and exiting at Creedmoor Road (Exit 9).

Drivers should turn left, go under the interstate and then turn left to travel west.


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  • Pierre Tong Apr 8, 9:47 a.m.
    user avatar

    I'm interested to see what happens with this project though - I think it'll help congestion on I-540 but the side streets that feed into I-540 will definitely be negatively impacted (have fun Falls of Neuse!)

    Everyone is going to hate me for saying it but I-540 should have been tolled in the northern Wake County section as well. You'll be able to control congestion better if people connect driving to paying a cost to use a road. It would make people reconsider moving somewhere due to the tolls (or slow down development) and a toll during just rush hours might encourage people to change their hours or driving habits so everyone isn't out on the road at the same time. People do pay for roads now through registration fees and gas taxes but those are indirect costs and it still feels like you can drive on the roads for free.

  • Andrew Stephenson Apr 8, 9:44 a.m.
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    View quoted thread

    It's not so much the planning that costs more, but the execution. A 6 lane road costs less than an 8 or 10 lane. The 540 ramps like at 401 cost more to do than the one at Buffaloe Rd. They are only able to budget so many elaborate ramps per cycle with the budget they are given.

  • Pierre Tong Apr 8, 9:30 a.m.
    user avatar

    As someone who works in traffic engineering (I didn't work on this project haha), I'm confident that there was significant planning put into the design of I-540 since I see the process that all the roadway projects around here. Traffic forecasting though is what we call a "Scientifically Wild ___ Guess" - there are so many variables that can change that the model we base our numbers on could widely change due to the economy, people suddenly moving to a new area etc... They do try and take all the potential development in the immediate areas in account for projects but that doesn't necessarily account for farther out places like Wake Forest/Rolesville which has blown up in recent years or rezoning of land uses approved after the project is built. So it's not really bad planning - there was an honest attempt to plan but it's just that the planning process is not perfect or accurate, just like weather forecasting :)

  • Kevin Weidner Apr 7, 11:30 p.m.
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    I look forward to sitting in traffic on Six Forks Road in lieu of sitting in traffic on 540 once this is completed.
    There are currently 2 left turn lanes off of Six Forks road north onto I-540 west which funnel into one lane. There is also a single lane for travelers going south on Six Forks which merges into these 2 before they funnel into a single lane for merging onto 540 west.
    Adding a "Ramp Meter" (Stop Light) to the bottom of the on ramp while you have three lanes feeding into it is going to be a nightmare.
    Perhaps a better idea might be reclaiming the concrete on I-40 at the Knightdale bypass interchange that is no longer used and repurposing it to widen the Six Forks merge lane for 540 to 2 Lanes for the same distance the current lane on I-40 is blocked off.
    If that idea proves to costly, perhaps we could pay for a study, two years of planning, and then the 24 month installation of a 2 lane round-about aka NCSU Belltower.
    Please don't forget to bring the barrel monster.

  • John Kramer Apr 7, 10:26 p.m.
    user avatar

    They tried this in DC in the 80's I believe. It was a waste of money, did not work. Hmmmm.

  • Henry Cooper Apr 7, 8:33 p.m.
    user avatar

    View quoted thread

    I get what you are saying but with the data available we should plan better.

    They had all the info I quoted so I don't understand how they missed it. The whole point was to plan for the future. This was advertised as being the plan for traffic thru 2030 in this area. Where was the foresight for that? Now it costs more to add to it and causes a traffic mess for a year.

    I don't understand how planning needed a larger budget to recognize what was needed. It was the same survey cost regardless of the number of lanes later installed. It was the same design cost or a minimal diff as I bet they had staff DOT engineers doing or approving the design.

    I am not thinking taxes for one year. I just don't see how planning/executing correctly at that time on readily avail data would have cost more in the long run. Total cost is now higher without a doubt.

  • Andrew Stephenson Apr 7, 7:09 p.m.
    user avatar

    View quoted thread

    If you're willing to take a tax hike, they are willing to accept a larger budget so they can plan further in the future.

  • Henry Cooper Apr 7, 6:48 p.m.
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    Well Thanks DOT!! Nothing but poor planning... There is nothing unexpected as far as growth in that area and that ramp has been a mess since day one (which isn't that long ago in highway building years).

    Why didn't you plan properly? I have no doubt doing it this way is a good 3 times as expensive as it would have been originally and traffic in that area was SO PREDICTABLE.,..

    The state/local govt should know exactly what is needed as they control building of anything via permits (homes, apts, businesses). They set the occupancy levels in those places. They know traffic flows by the sensors we paid for that are already there, They know how many cars are already registered in the area.

    This is the garbage that needs to stop and it is prevalent throughout local, state, and Fed. It is just a sheer lack of respect for the dollars we earn and give to them. There should be people losing their jobs over this. This is 10's of millions of dollars wasted I bet.

  • Jim Frei Apr 7, 4:29 p.m.
    user avatar

    Hey DOT - add the toll collectors to I-540. You're being unfair to the folks using the NC 540 segment.