The N.C. Department of Transportation plans to make big changes where U.S. 70 meets Hammond Road and Timber Drive, and will present two options to the public on Tuesday evening.
The first involves building a bridge that will carry Hammond Road/Timber Drive over U.S. 70. The second would be a type of intersection that's never been tried in North Carolina before.
The bridge would cost nearly twice as much ($18 million), require more real estate, take longer to build and disrupt traffic more while it's under construction, said Zahid Baloch, the project engineer for NCDOT. But the alternative, called a "continuous flow intersection," might still be a hard sell.
“It’s a new concept, but it works very well," Baloch said. "And looking at the cost, it does make sense to at least provide that option for the public, get their feedback and see how they feel about it.”
The continuous flow model is designed to move traffic more smoothly and safely through big intersections by beginning the process of turning left several hundred feet before the two roads meet.
In this case, drivers wishing to turn left from Timber Drive or Hammond Road onto U.S. 70 would move into two left-turn lanes at traffic lights before they get to the main intersection. When the lights turn green, they'll cross the stopped on-coming traffic, then move to U.S. 70 where they'll turn left.
Drivers wishing to left from U.S. 70 on to either Timber Drive or Hammond Road would pass through the main intersection to separate traffic lights down the road, where they can make a U-turn and drive back to make a right turn.
Continuous flow intersections are one strategy traffic engineers have come up with to reduce congestion and accidents at busy intersections by changing the way drivers make left turns. Another is the diverging diamond interchange, which NCDOT plans to build at several places around the Triangle in coming years.
Utah has built several continuous flow intersections, but they remain rare nationwide. NCDOT has one in the works on N.C. 150 near Lake Norman, but none have been built yet in North Carolina.
The bridge would also smooth the flow of traffic, with left turns being handled by a single-point interchange on U.S. 70 under the bridge.
Putting U.S. 70 on a bridge over Hammond Road/Timber Drive instead would allow through-traffic on the main road to move freely without stopping. But Baloch said there's not room to build the approaches to a U.S. 70 bridge without blocking access to side streets and businesses, including the Garner Towne Square shopping center.
NCDOT has determined that it can't leave the intersection as it is. As many as 37,000 cars and trucks a day now pass through the intersection on U.S. 70 alone, and that number is expected to grow to as many as 52,200 by 2040, Baloch said.
NCDOT will present the two options from 4 to 7 p.m. Tuesday at The Capital Church, 1308 U.S. 70 in Garner. People can provide feedback there or to Baloch at firstname.lastname@example.org or 1548 Mail Service Center, Raleigh, N.C., 27699 by April 27.
For more information, including diagrams of the two proposals, go to www.ncdot.gov/projects/publicmeetings and look for U-5744.