Here’s how a diverging diamond interchange works
Drivers on Interstate 40 southeast of Raleigh will begin to notice some road work, as the effort to widen an 11-mile stretch of the highway between Interstate 440 and N.C. 42 gets underway.
Starting Monday, contractors for the N.C. Department of Transportation will begin shifting eastbound lanes away from the median between Rock Quarry Road and U.S. 70 Business. When they’re done, which could take a week, they’ll do the same on the westbound side.
It’s the start of a multi-year effort to add two lanes to each side of I-40 between Raleigh and the exit at N.C. 42 in the Cleveland community of Johnston County. The $330 million project also involves reconfiguring the interchange at N.C. 42, with a new traffic pattern and new ramps that will give drivers the option of getting on or off at nearby Cleveland Road.
As the lanes on I-40 are shifted, they will get narrower, from 12 feet to 11, to provide space for work crews. Sometime in November, concrete barriers will be placed along the inside lane to separate traffic from workers. The speed limit will also be reduced, from 65 mph to 60.
The work at the N.C. 42 interchange isn’t scheduled to get started until the fall of 2020. The whole project is expected to be completed in 2022.