Although everyone at last week’s City Hall Meeting at the Oasis Shriners hall already had heard, NC transportation spokesman Warren Cooksey couldn’t resist starting his report on state projects with the long-awaited good news: The last piece of the I-485 Charlotte Outer Belt will open on June 5.
The opening of the last stretch of roadway, through University City, marks the completion of Charlotte’s 67-mile belt road 26 years and 11 months after the project’s 1988 groundbreaking. Waiting does have its benefits: The 5.7-mile final leg in University City will open with four traffic lanes in each direction vs. 2 lanes on the early sections of roadway.
New design features abound
Our stretch of the Outer Belt also has some unique design features.
- The Prosperity Church Road exit features a “split-diamond” interchange that will allow traffic to exit I-485 onto a one-way service road connected to three separate streets through a series of roundabouts. Charlotte planners suggested this design in 1999 and created a land-use plan to generate walkable urban-style communities on both sides of the interchange, now known as Prosperity Villages.
- The Mallard Creek Road interchange uses a “Diverging Diamond” Interchange, where two directions of traffic temporarily cross to the left side of the road. This design allows high volumes of traffic to move through an intersection without increasing the number of lanes and traffic signals. The results include less congestion, improved safety and easier access to I-485, says the NC Transportation Department.
The I-85 interchange employs the first “turbine” interchange in North Carolina. The turbine design features smaller, single-span bridges with smaller columns and flatter roadway profiles than used in traditional major interchanges, the state Transportation Department says. This innovative design circles all left-turning traffic around a central bridge in a counterclockwise direction, improving sight distances for motorists and allowing a safer transition between the two interstates at highway speeds.
Speed limit now 70 mph on I-485
The state also announced last week that it is raising the speed limit on the entire outer belt from 65 mph to 70 mph. A NC Transportation Department news release said that the increase reflects the highway’s design, which can safely accommodate the higher speed, as well as the fact that most drivers already travel the road at 70-75 mph.