A-ha! So saving money does explain 485’s bargain-basement construction. Money quote:

Crews are putting up tall lights to illuminate I-485 interchanges in southwest Charlotte, but that work was already in progress before the deadly crash, said Tom Thrower, the state traffic engineer responsible for the Charlotte area. They are part of a recent widening project on I-485 and will be the freeway’s first lights.

Drivers such as Dottie Coplon complain that lack of lighting makes I-485 dangerous. “There are no lights. You can’t see a darn thing,” said Coplon, who lives near the Providence Road interchange. “Unless you know exactly where you are going, you can get in the wrong place, drunk or sober. They need lighting and larger signs.”

Thrower said the state saved money by building the freeway without powerful median and interchange lights, such as those found on much of I-77 and I-85. He said he believes all I-485 interchanges should be illuminated.

But his boss, Kevin Lacy, the state’s chief traffic engineer, said overhead lighting likely would not have kept Franklin from entering the exit ramp. That busy South Tryon Street interchange is a standard diamond design, with exit and entrance ramps spaced far apart.

“Lighting is always a controversial issue. I’m personally not convinced it would help with wrong-way crashes,” Lacy said. The driver would have missed at least two Wrong Way signs in his drive down the N.C. 49 ramp.

Thus Lacy reveals he does understand what is going on. The purpose of the lighting is not to shine more light on Wrong Way signs. Background illumination of interchanges gives drivers visual cues about the layout of the entire interchange, not just where their headlights throw light. It is easy to imagine how this helps drivers understand where to turn.

Suppose you are driving up NC 16 from Waxhaw and you want to take 485 back to Pineville. You know you need to turn “left” onto 485 to head back towards Pineville. You turn left at the first traffic light at the interchange, however, and you will headed the wrong way down the exit ramp. To do that you would have to ignore the signs, yes, but it is also likely you did not see the other entrance to the Beltway further down the road. Nor is it possible to discern in the dark that with a right turn at that intersection you end up going “left” towards Pineville. Add in the lack of overhead signage telling you which lane you use to go to Pineville and it is easy to see how impaired drivers might get confused.

None of this is particularly complicated. Heavily used interchanges with lots of commerical and retail traffic need lighting. But instead NC DOT spends thousands on companies that provide kickbacks to employees. Same old, same old. The continuing criminal conspiracy that passes for state government just rolls on.