Plans finalized for road repair

September 29, 2017 by  

Finishing touches were recently given to plans for the widening of Interstate 440 on the west side of Raleigh, and they include revamping a difficult interchange.

The North Carolina Department of Transportation (DOT) said it will use the construction period as an opportunity to install a design called a “diverging diamond” at the spot where traffic enters I-440 from Western Boulevard.

Jim Dunlop, a DOT engineer, said the interchange was built in 1959, when Raleigh’s traffic was far less congested, and is now overwhelmed. The upcoming project to widen the beltway will give DOT the opportunity to replace it. Of all the possible configurations available, the diverging diamond seems to be the best choice.

In such an interchange, traffic turning right remains in the right lane, but traffic heading straight through the intersection, or turning left, is handled differently. In these cases, traffic, controlled by a stop light, will cross to the opposite side of the road before swinging back to the correct side at a second signal. This means that motorists will drive on the left for a short distance, which enables them to make a left turn without crossing in front of traffic.

Although it may sound complex, Dunlop says drivers take to the configuration easily. A diverging diamond in Greensboro has worked well, he says, and overall, this type of interchange has reduced injures by up to 40%.

For projects that impact many people, officials sometimes work with a newsletter printing company to create an update letter for residents.